Hawaii Aquaponics Workforce Training Class Questions by Category
BE AWARE: Making your own feed or using natural feeds can cause nutrient deficiencies in fish and plants. It is important that you know the nutrient requirements of the species you are raising so that proper supplementation can be incorporated. The trend toward increasing plant ingredients in fish diets was creating diets that had more minerals like Phosphorus in an unavailable form (phytate - which also binds zinc). This usually requires an increase in phosphorus supplementation using an available form like calcium monophosphate dibasic (which also supplies calcium). Then there are interrelationships among minerals, like the balance between calcium and phosphorus that affects digestion and excretion.
1. Can fish feed be produced at home?
There are hobbyist that do produce their own fish feeds at home. Some items used as fish feed are duckweed and azolla which are high in protein content. There are also individuals that use black soldier fly larvae and other types of insect larvae, which are high in protein and lipid content. Some people feed these items directly to the fish and supplement with commercial feed. Others have gone as far as to mix these ingredients with other required ingredients and create their own pellets. The most important aspect of creating your own feed is know the nutrient requirements of the fish and the nutrient requirements of the plants. Fish require specific levels of essential amino acids and essential fatty acids for proper growth and development. Homemade feeds usually result in fish that grow much slower than those fed special formulated commercial diets. Homemade feed is viable for home systems in which the family can allow extra time for fish growth. Homemade feed is not currently viable for anyone who wishes to grow commercially due to the fact that slowed fish growth affects income. Current research is being conducted on how to raise insects at a commercial viable rate; this is something that will take years to develop and may not be viable due to expenses it would take to run a commercial operation. There is a lot of research being conducted on how to use other plant sources (such as moringa leaf meal) as protein but this may also not be commercially viable due to slowed growth in fish as well as growing the trees at a commercially viable rate.
2. How often should I feed my fish?
For the microsystem we recommend feeding two times a day as much at the fish will eat in 5 minutes. This seems to provide the proper amount of nutrients to the plants. If your ammonia levels start to rise too much decrease or cease feeding the fish until levels are safe. If you notice that there are not enough nutrients being produced increase feeding rate.
For commercial systems it is recommended that feeding rate ratio be in the range; dependent on plant crop, of 60 to 100g/m2/day (Rakocy 2011). The smaller value should be used for small, slow growing plants and the higher value used for large, fast growing plants. Fish in commercial systems are often fed twice a day as much as they can eat in 30 minutes.
BE AWARE: Extra food should be removed from tanks. Food that the fish do not eat will decompose and affect water quality negatively.
3. Fish feed - where do I get it, or can fish feed be produced a home?
Del’s Farm Supply in Kahului has commercial koi and tilapia feed. You can produce your own feed at home but to have optimal growth of fish and to sustain healthy fish you need to know their nutrient requirements and this varies from species to species.
4. What alternate fish food sources are available?
Besides commercial feed which is best for optimal health and growth of fish other things that have been used as fish feed are azolla, duckweed, different varieties of insect adults/larvae, and dog food. If you mean what is an alternative source of protein besides fish meal than the answer is soybean meal is the most researched currently, other things being researched include a range of different types of plants for their protein content and amino acid composition as well as different insects adults/larvae for their protein content, amino acid composition, lipid content, and fatty acid composition.
5. Making your own organic food for your fish?
This is possible by knowing the nutrient requirements of the species you are raising and being able to meet those requirements based on what you plan to use as your organic food source. Many hobbyist use multiple ingredients to produce their own pelleted feeds or the just feed something like duckweed and azolla directly to the fish and supplement with commercial feeds.
6. I wonder how I am going to make my own Tilapia feed for the system on the farm?
You can research different ways to make feed. Online you can find a booklet called “Make your own tilapia feed; a guide for farming families in America samoa” that teaches you how to do this.
7. I wonder what can be used from a local source for fish food. I would like to know if there is a non-GMO source of soybean meal?
I hate to be the bearer of bad news but according to the Center for Food Safety 91% of soybeans are genetically modified. Cross pollination occurs often. However, there are some individuals that claim to export non GMO soybean meal. Note that the orders placed to these companies are in bulk quantities and they may not provide small amounts at a time. Here is the list:
American Health & Nutrition Inc.
Attn: Mr. Michael Schachter
3990 Varsity Drive
Ann Arbor, MI 48108
Phone: (734) 677-5570
Fax: (734) 677-5572
Archer Daniels Midland Co.
Attn: Mr. Scott Fredericksen
4666 Fairies Parkway
Decatur, IL 62525
Phone: (217) 424-5422
Fax: (217) 424-5681
Continental Grain Company
Attn: Mr Paul D. Smolen
277 Park Avenue
New York, NY 10172
Phone: (212) 207-5100
Fax: (212) 838-1551
International Farmers Grain, Inc.
Attn: Dr. Robert Ross
460 West 34th St.
New York, NY 10001
Phone: (212) 279-9525
Fax: (212) 629-3147
International Proteins Corp.
Attn: Mr. Eric H. Jackson
46 East Fourth S treet Ste. 1120
St. Paul, MN 55101
Phone: (612) 222-4472
Fax: (651) 222-4495
Iowa Soy Specialists
Attn: Mr. Dan Van Steenhuyse
105 M Ave. North
Vinton IA 52349
Phone: (319) 472- 5656
Fax: (319) 472- 4568
Attn: Mr. Paul Lang
798 Highway 6
Grinnell, IA 50112-8004
Phone: (515) 236-0852
Fax: (515) 236-4835
Northland Organic Foods
Attn: Mr. Peter Shortridge
462 Holly Ave.
St Paul MN 55102
Phone: (651) 221 0855
Fax: (651) 221 08 56
Pioneer Hi-Bred International, Inc.
Attn: Mr. Nicholas Frey
7100 Northwest 62nd Ave.
P.O. Box 1150
Johnston, IA 50131-1150
Phone: (515) 254-2737
Fax: (515) 254-2744
U.S. Soy LLC
Attn: Mr. James Skiff
2808 Thomason Dr.
Mattoon, IL 61938
Phone: (217) 235-1020
Fax: (217) 235 -1006
Others are listed at Internet site: http://www.soyatech.com (Soya & Oilseed Bluebook Directory)
8. I wonder why there isn’t a more natural way to feed the fish rather than fish meal?
There are more natural ways to feed fish rather than fish meal. However, these ways are not commercially viable for multiple reasons. The more natural ways of feeding fish lack the nutrient and mineral compositions needed for optimal fish growth and health, there are also not current methods of commercially producing these types of feeds (excluding the use of soybean meal). These types of feeds would be expensive to produce at a commercial level at this point thus making the feeds expensive for farmers (which is true of all fish feed currently as prices rise due to the cost of fish oil and fish meal). Natural feeds are viable for small systems but is not yet a viable pathway for commercial based systems. Research will continue to be conducted in this area and soon hopefully there will be multiple solutions, or at least one solution.
9. Local sources for organic fish food that can produced on my land.
Currently there are no local sources for organic fish food; organic fish food can be sourced from the mainland; you will receive a handout with the website and ingredient list of these feeds. Use of duckweed, azolla, and black soldier fly larvae mixed with vitamins and minerals would be the best way to produce your own organic fish food.
10. How to use worms, ducks, and chicken pens over ponds for fish and plant food. And do the chickens and ducks make the water too acidic for the fish and how to remedy this?
BE AWARE THAT HAVING FOWL FECES AROUND YOUR FOOD SUPPLY GREATLY DECREASES FOOD SAFETY. FOWL FECES MAY CONTAIN A VARIETY OF MICROSCOPIC PATHOGENS THAT CAN EASILY CAUSE SECONDARY CONTAMINATION OF PLANTS AND FISH. ALSO PLEASE NOTE THAT: Birds and snails can increase the risk of trematodes such as Clinostomum spp., in tilapia especially in extensive earthen pond systems. It might therefore be necessary to prevent snails and birds from accessing the growing unit and remove or eradicate the present snail population from the water. Biological control is today available.
Chickens: “THE VERTICAL FARM, Food Production of the Future” by the Columbia University Department of Environmental Health Sciences states that an egg-laying hen poops 40 lbs per annum. This converts to about 50g per day. Use this number with the weight of fish in the pond. Say you have 2,000 fingerlings that are 30g each. 30g x 2000 fish = 60kg of fish. If I want the “poop” component of their diet to be 1% of their body mass per day I then need 600g of poop at 2% I need 1200g. Divide this by each hen’s contribution of 50g. 600 / 50 = 12 hens at 1% or 1200/50= 24 hens at 2%. As your fish weight increases in the pond so will your number of chickens have to increase to keep up with the 1-2% body mass of fish. A consideration in this matter is that chicken debris (feathers, feed, etc.) can clog plumbing. As for water quality issues, yes they could arise; you will have to carefully monitor your water quality, decrease number of chickens if ammonia starts to rise or pH starts to drop. You can also add calcium or potassium hydroxide to increase pH as well as putting oyster shells in your system.
Ducks: will be the same concept as the chickens, I have given you the formula for calculating the number of fowl needed per how much they “poop” you will just have to research how many grams per day a duck defecates.
Worms: Eisenia fetida, commonly known as California red crawlers are best suited for decomposing waste in aquaponics and are the most widely used worm for composting. They thrive in rich organic matter, can tolerate high temperatures, and can withstand the flood portion of the flood and drain cycle in the aquaponic grow beds. Worms play a key role in decomposing fish and plant waste that accumulates in the gravel grow beds. Worms both take advantage of this material and release the minerals therein for plant use, and also keep the gravel beds free from clogging.
11. I wonder what has research shown to be a valid organic source of organic feed?
Please see handout with websites of certified organic fish feed and the ingredients.
Also, be aware that feeding your fish organic feed will not allow you to label the fish you sale as organic.
Here is why: http://www.worldwatch.org/node/5755
“Aquaculture Operations Seek Organic Certification"
A USDA organic aquaculture would not allow fish farms to catch fish for fishmeal, a proposal says. Of the several proposed or available labels for seafood products, none are as divisive as organic. As the aquaculture, or fish farming, industry continues its rapid expansion, some U.S. environmental groups have called on the government to set organic standards for aquaculture. Their hopes are that the booming organic market, with its higher premium, would motivate fish farms to clean up their acts. Others remain unconvinced that an organic fish market could address aquaculture's environmental concerns without ruining the credibility of the U.S. Department of Agriculture (USDA) organic label. The specifics of how marine fish species can be certified as organic are still uncertain. Whatever the outcome, the fates of global fisheries and the organic industry as a whole may be at stake.
A Fish Feed Dilemma
Aquaculture was once considered the safe alternative to a seafood industry that has driven global fish species toward extinction. Now fish farms are labeled by some environmentalists as a more destructive option. Tremendous concentrations of fish waste and antibiotics pollute coastal waters, and fish escapees threaten the ecological balance of wild fish communities. Some aquaculture operations, such as Hawaii's Kona Blue Water Farms, are implementing more expensive measures they say help to better protect the environment.
The United States passed Japan last year as the second largest seafood importer, behind the European Union, so a new organic demand may have global implications. But the USDA National Organic Standards Board is struggling over the first step in the organic fish process: what would these fish eat? A panel of aquaculture experts suggested that fish caught in the wild should be permitted to eat fishmeal in "organic" aquacultures, and over time more fishmeal would have to be farm-raised.
A coalition of 44 environmental organizations protested the proposal, which they said would violate organic rules that require organic animals to be fed organic food. Plus, they said it may threaten the survival of smaller fish, which are disappearing as they are caught to feed carnivorous farmed fish, such as salmon or trout. Commercial fishing dedicated to fishmeal or fish oil now amounts to 32 million tons per year, or 37 percent of all fishing, compared to 7.7 percent in 1948, according to a University of British Columbia study.”
12. I wonder what sustainable food sources exist for the fish?
Research is ongoing in this area as many people are interested in the need for sustainable, and even organic, fish diets. Be aware that Vegetable-derived proteins have successfully replaced fishmeal in feeds for fishes, but vegetable-derived oils have not successfully been incorporated into the diets. Vegetable-derived oils do not contain the same fatty acid chains that fish oils provide. Fish need certain essential fatty acids for proper growth and function. Some fish (omnivorous) have the capacity to desaturate and elongate plant oils into usable fatty acids while others do not.
13. I wonder how do we find sustainable feed sources for fish without increasing reliance on GMO soy?
Research, research, and more research. There are many universities with aquaculture programs with a focus on fish nutrition. These universities are attempting to implement plant proteins as a source of replacement for fishmeal. The most common issue is making sure the composition of these proteins meets the needs of fish nutrient requirements. Fish needs certain amounts of essential amino acids for proper growth and function. Thus far, most research is being done using soy; this is most likely due to the fact that Monsanto provides most funding for research in this area. I personally feel that insects are a better means as an ingredient due to the fact they have a more proper protein and lipid composition than plants; however production insects at a commercial level could prove to be difficult.
1. What fish can I raise in an aquaponics system?
How can the Aquaculture Development Program help me?
ADP's services include providing information on species and site opportunities, assisting with permits, assessing farm sites, identifying sources of financing, and advising on marketing and business development. The ADP office is located downtown Honolulu at 1177 Alakea Street, Room 400, Honolulu, HI 96813, Telephone: (808) 587-0030. Fax (808) 587-0033. E-mail: email@example.com
The most commonly cultured fish in commercial aquaponics (around the globe) are tilapia (Nile tilapia, Oreochromis niloticus niloticus) species (Rakocy 2004). Other systems have used channel catfish (Ictalurus punctatus), largemouth bass (Micropterus salmoides), crappies (Pomoxis), rainbow trout (Oncorhynchus mykiss), pacu (Colossoma spp), carp (Cyprinus spp), goldfish (Carassius spp) (Rakocy 1999a) perch (Perca spp), Arctic char (Salvelinus alpinus), Barramundi (Lates calcarifer), and Murray cod (Maccullochella peelii) (Diver 2006). Hybrid striped bass (Morone chrysops x saxatilis) perform poorly in these systems due to their intolerance of high potassium levels, which are needed for plant growth (Rakocy 1999a). Selection of species to use depends on the situation. Personal systems can be filled with species that are considered delectable to the owner. Commercial systems rely on species that are profitable depending on market demands. When selecting a species make sure that is a species that is allowed into your state. You can do this by going to your states USDA website and looking at the species restriction lists.
According to the USDA for the state of Hawaii here are current Products:
Hawaii enjoys a widespread reputation for high quality seafood. Aquaculture has diversified the selection of Island seafood and produces both warm and coldwater fish and shellfish, grown in fresh, brackish, and saltwater. Here is a listing of major existing commercial products and species in the research pipeline.
Commercial Products Being Grown
Abalone (red, Haliotus rufens and Japanese, Haliotus discus hanai)
Aquatic snails (Pomacea sp.)
Carp (Ctenopharyngodon idellus, Hypothalmichthys mollitrix)
Catfish (Clarius fuscus)
Freshwater ornamental fish and aquatic plants (various species)
Broodstock and juvenile shrimp (L. vannamei, L. monodon, L. stylirostris)
Freshwater prawns (Macrobrachium rosenbergii)
Giant clams (Tridacna sp.)
Japanese Flounder (hirame, Parlichthys olivaceus)
Kahala (amberjack, Seriola rivoliana)
Lobster (Homarus americanus)
Marine ornamental fish and plants (various species)
Marine ornamental invertebrates (various species)
Marine shrimp for food (Penaeus vannamei)
Microalgae (Spirulina sp., Hematococcus sp.)
Milkfish (Chanos chanos)
Moi (Pacific threadfin)
Mullet (Mugil cephalus)
Seahorses (various species)
Seaweed or sea vegetables (Gracilaria sp.)
Seed clams (Mercenaria mercenaria)
Seed oysters and clams (Crassostrea gigas, Ostrea edulis, Mercenaria sp.)
Seed pearl oysters (Pinctada fucata, P. margartifera)
Tilapia (Tilapia sp.)
Active Research Underway
Deepwater snappers (opakapaka, Pristipomoides Filamentosus; ehu, Etelis carbunculus; onaga, E. coruscans)
Groupers (various species)
Jacks (various species)
Marine ornamental fish (various species)
Marine ornamental invertebrates (various species)
Sturgeon (various species)
2. What types of edible fish can be raised?
Any type of freshwater/marine (saltwater aquaponics) fish that is allowed into the state of Hawaii and can tolerate the water quality parameters of the plant crop being raised.
3. Can local crayfish-prawns be grown?
They can but not for profit. These are highly cannibalistic species that also need places to hide. Therefore you could raise a few for your family but not enough for commercial sales. See the next question for a detailed answer on how to raise them in your aquaponic system.
4. I wonder how I can raise crawfish for gumbo in my system?
You would have to raise them at very low densities (highly cannibalistic) in cages with a hiding place (piece of PVC) in the raft tank. Let me explain. Crawfish like hiding places, if you were to put hiding places in the fish tank you would obstruct the bottom and solid waste would be hard to remove. You plant roots – thus the cages – the cages also prevent them from killing one another by forced separation. Commercially viable production is not possible but there is potential to raise enough just for your family to eat.
5. I wonder if is it possible to have a saltwater/brackish/freshwater aquaponics system and could additional sea life be introduced into the system (i.e. snails, prawns, shrimp, oopu,) along with the fish?
PLEASE NOTE THAT: Birds and snails can increase the risk of trematodes such as Clinostomum spp., in tilapia especially in extensive earthen pond systems. It might therefore be necessary to prevent snails and birds from accessing the growing unit and remove or eradicate the present snail population from the water. Biological control is today available.
Saltwater aquaponics is in its beginning stages but there is hope for the future of this idea. See above questions for information on crawfish/prawns. Low salinity shrimp culture may have potential. These can be raised at densities of 5 kg/m3 (Rakocy 2011). Biggest challenge is finding an ionic composition suitable for both shrimp and hydroponic plant crop. Species most commonly used is the Pacific white shrimp (Litopenaeus vannamei). Minimum salinity of 2 parts per thousand (or 2,000ppm) can be used which is the nutrient concentration of most hydroponic solutions (Rakocy 2011). The problem is in most hydroponic solutions the sodium and chloride ions are <50ppm while shrimp require higher concentrations for osmoregulation. The good news is that shrimp like high levels of potassium, magnesium, manganese, and sulfate ions which will benefit the plant crop. Crops should be chosen based on their ability to tolerate high concentrations of sodium and chloride ions. Tomatoes can tolerate high concentrations of sodium chloride (Rakocy 2011). In intensive culture 250 shrimp/m3 are common (Rakocy 2011). However you must decide if you are doing this commercially if you can raise enough shrimp to economically outcompete the fish you could raise. At the University of the Virgin Islands (UVI) they had 4 rearing tanks that were 2,060 gallons each. If they stocked the shrimp at the common rate and cultured them for 16 weeks to a size of 20g (0.7 oz) at staggered production with the assumption of a 90% survival rate there would be 13 harvests a year at 77.3 lbs. per harvest (Rakocy 2011). That gives a total annual production of 1,005 lbs. with shrimp being sold at around $8.00/lb (in the Virgin islands); the current annual tilapia production for UVI is 11,000lbs at $2.50/lb. Rakocy states that more space could be devoted to shrimp rearing and there could be a reduction in plant growing area to increase profit. However the information is all based on assumptions and many areas still need to be researched.
Australia has a majority of the research on saltwater aquaponics. Please see the following link for an article on this. http://aquaponicsjournal.com/docs/articles/Seaweed-is-Common-Denominator.pdf
1. Will this course cover hatchery operations? If not, where could I purchase fingerlings?
This course will not cover hatchery operations. See below question for an answer on where to source fingerlings.
2. Where do you get fingerlings from?
There are individuals on the island that sell tilapia fingerlings but they are not certified. The pet shop at the maui mall can source them via special order. Fingerlings can also be sourced from the mainland. Once the HAWM greenhouse is up and running we plan to source APHIS certified tilapia and provided them to the local community. It is personal choice whether you want certified fingerlings or not. Food safety is greatly increased when you do not put “ditch fish” into your system. If you choose to do this I highly recommend quarantining your fish for an extended period of time and treat them prior to introduction into your system.
1. Common disease of fish?
PLEASE NOTE: If fish become ill they must be removed from the aquaponics system to be treated. Treatment within the system will have a toxic affect on the plants. All research how you treat your fish before applying chemicals, some chemicals are not safe for foodfish; any chemicals can be used on ornamentals since they will not be used for consumption.
Common disease varies based on species being raised. I will put the most common diseases for tilapia. If you plan on raising another species then you can inform me of that species and I will get the information for that species. A Few Examples of Common Parasitic Diseases in Tilapia:
Trematodes Clinostomum spp. (Digenenan). The risk of Clinostomum spp. problems is highest when tilapia is farmed in ponds that can be accessed by snails and birds. Symptoms: Clinostomum spp. will normally cause the formation of yellow or white grubs on the skin of the tilapia. In severe case, the parasite can cause skin haemorrhage and death. Treatment: The best cause of action is normally to prevent snails and birds from accessing the pond and remove or eradicate the present snail population from the water. Biological control is today available.
Dactyolgyrus spp. (Monogenean) Young tilapia (juvenile and fingerling fish) is especially vulnerable to attacks from these parasites. Symptoms: Dactyolgyrus spp. can cause darkened skin, eroded fins and excessive mucus production in infested tilapia. Rapid movement of operculum is another common symptom. Young tilapia will often rapidly waste away. Treatment: Infested tilapia can be given formalin baths or hydrogen peroxide baths.
Argulus sp. Young tilapia (larval stages and fingerling fish) is especially vulnerable to attacks from this parasite. Symptoms: Argulus sp. can cause skin irritation and general weakness in infested fish. When the skin is damaged and the fish weakened, it is common for bacteria take advantage of the situation and cause secondary infections. Treatment: Argulus sp. infestations can be treated with organophosphates.
Ciliates Ichthyophthirius multifilis. If you’re an aquarist, you have most likely heard about this parasite before. Among aquarists, the illness caused by the parasite Ichthyophthirius multifilis is referred to as Ich or White Spot Disease. For tilapia, the problem is most severe in larval stages. Symptoms: The parasites will cause white cysts to form on the skin of the fish. These cysts look like white spots or small grains of salt. Infected fish will often scratch themselves against rough surfaces in the environment in an effort to rid themselves of the cysts. Ichthyophthirius multifilis can lead to stunted growth and death in tilapia. Treatment: Many different Ich treatments are available for aquarists, e.g. repeated formalin baths or increased salinity. Some treatments that are practical for hobby aquariums are not feasible for large commercial tilapia cultures.
Trichodina spp. Young tilapia is especially vulnerable to Trichodina spp. and this parasite can cause substantial mortality in hatchery and nursery phases. Symptoms: A tilapia infested with Trichodina spp. can start swimming in an erratic fashion, scrape itself against rough surfaces and jump out of the water. The fins can erode, the gills can develop hyperplasia and skin ulcers can appear. Opened operculum can also be a sign of Trichodina spp. Treatment: Infested tilapia can be bathed in saltwater, formalin, hydrogen peroxide or potassium permanganate. Many tilapia hatcheries always keep the water salinity in the 5-10 ppt range to prevent protozoan ciliates such as Trichodina spp.
Dinoflagellates Amyloodinium spp. These parasites are only found in tilapia living in brackish waters with a salt content of 10-15 ppt, not in freshwater. Symptoms: A tilapia infested with Amyloodinium spp. will often eat less than normally. Flashing and accumulation of mucus are two other common signs. Treatment: Since the parasites are adapted to brackish conditions, they can be combated with fresh water baths.
Crustacean copepods Lernea spp. Lernea spp. can have a negative effect on mouth breeding in tilapia. Symptoms: In infested tilapia, it is common to see white spots on the skin. These spots consist of tiny curled up worms that are embedded in the skin. In an effort to get rid of the worms, the fish will often rub itself against rough surfaces in the environment. Treatment: Lernea spp. infestations can be treated with organophosphates.
Hirudidae Leeches. Leeches will normally only be a problem for tilapia fish that is already weakened, e.g. by other parasites, stress or improper environmental conditions. Symptoms: For adult fish, a severe leech attack with a high number of leaches is normally required before any signs of anemia become noticeable. Young fish are more sensitive. Treatment: Leeches can be treated with organophosphates.
Major diseases affecting tilapia during the farming cycle
2. What are the nutritional needs of the fish?
Two of the major nutrient groups for fish are protein and lipid. NRC 2011 states in Table 1-2 a variety of protein requirements for different species from different sources. These protein requirements start as low as 30% for Nile tilapia (Oreochromis niloticus L.) and go as high as 55% for red sea bream (Pagellus bogaraveo) and yellowtail (Lutjanus griseus). Aquaculture feeds average protein levels at 28-32% for catfish, 32-38% for tilapia, and 38-42% for hybrid striped bass (Morone chrysops x saxatilis) (Craig and Helfrich 2002). Dietary protein requirements decrease as the fish approaches maturity (NRC 2011). Dietary protein requirements are generally lower for herbivorous fish than for carnivorous fish. There are two components of the dietary protein requirement. The first is that fish need essential amino acids, those which cannot be synthesized by the fish at a rate that is commensurate with their needs (NRC 2011). The second is the need for non-essential amino acids, or sufficient amino nitrogen to enable the fish to synthesize non-essential amino acids (NRC 2011). Fish require the 10 essential amino acids (EAA) for growth. The EAA for all fish are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The NRC (2011) contains multiple tables for different species of fish and the required percentage of dry diet for multiple essential amino acids. These values range from as low as 0.1% up to 2.8% of the dry diet. These amino acids must be in the diet in balanced amounts to generate a satisfactory amino acid configuration before the fish flesh can be formed (Halver 1976). Fish that are fed diets lacking any one of these amino acids fail to grow (Halver 1957).
Normal growth and development of fish is also dependent on dietary lipids. Consideration of type of lipid along with protein and energy content of the diet is important in deciding the percentage of dietary lipid to be added to the diet (NRC 2011). Dietary lipids are sources of energy and of essential fatty acids (EFA); they contain both saturated and unsaturated fatty acids (NRC 2011). The EFA’s are in all biomembranes as components of phospholipids and precursors for eicosanoids, which fulfill a variety of metabolic functions (NRC 2011). The fluidity of membranes is dependent on the proper balance of saturated and unsaturated fatty acids; biomembranes cannot function normally at various temperatures if they are not in a fluid state (NRC 2011). The EFA requirement of fish varies qualitatively and quantitatively among species and during ontogeny of fish (early development and broodstock have critical requirements) and is linked to their capacity to elongate and desaturate fatty acids metabolically (NRC 2011, Tocher 2010). Table 1-14 (NRC 2011) shows the EFA requirements for multiple fish species from multiple sources. The environment (freshwater or marine) and trophic level (carnivore, omnivore, or herbivore) are major factors in EFA requirements (Tocher 2010). Freshwater species are able to desaturate and elongate fatty acids and generally require C18 polyunsaturated fatty acids (PUFAs; 18:2n-6 and 18:3n-3). Marine fish have a strict dietary requirement for HUFAs. This is due to evolutionary standards in which marine phytoplankton produce high levels of EPA (20:5n-3) and DHA (22:6n-3), whereas the freshwater phytoplankton have higher levels of the PUFAs with a reasonable amount of EPA but low levels of DHA (Tocher 2010). This means there was never any evolutionary pressure for marine fish to generate ways to elongate and desaturate PUFAs into HUFAs as there was for freshwater fish (Tocher 2010). Quantitative requirement for n-6 HUFA ARA has not yet been fully determined for marine fish and have received little attention in freshwater species (Tocher 2010). All fish need both n-3 and n-6 fatty acids even though the specific types used vary. Lipids are important as a source of dietary energy for all fish but to a greater extent for cold-water and marine fish that have limited access to dietary carbohydrates for energy (NRC 2011). Other important nutritional requirements for fish are vitamins and minerals; carbohydrates are also in fish diets but are not nutritionally essential for the fish.
1. Inter-island fish transporting?
I couldn’t find anything on the USDA website for the state of Hawaii’s inter-island fish transporting but have emailed someone in the aquaculture department and can answer as soon as I get a response.
1. What kinds of plants can I grow?
Almost any type of plant can be grown in an aquaponic system. It all depends on the nutrient availability in the water. High nitrate levels are good for the growth of leafy green vegetables. The high nitrates stimulate vegetative production which in turn inhibits fruit set (if energy is being used to produce the vegetation this energy is not being put towards fruit production). In aquaponics you can control the amount of nitrates by how often you clean the filter tank. Cleaning the filter tank less often allows for anaerobic zones to develop and denitrifying bacteria will grow in the absence of oxygen. Denitrifying bacteria remove nitrate by converting it into nitrogen gas (Rakocy 2011). The filter tank also plays a role in increasing the nutrient levels in the system. For the duration that solids are held in the filter tank between cleanings bacteria will break down organic matter and release inorganic nutrients that can be absorbed by plants through their roots. This process is called mineralization. Solids should be removed slowly from the system to ensure there is time for mineralization to occur. In Australia saltwater aquaponics is being used to raise seaweed. Algae can also be produced in aquaponics. Here is a list of things that have grown successfully in systems:
Simpson's Curled (Lettuce)
Oregon Sugar Pod (Peas)
Bloomsdale Savoy (Spinach)
White Bunching (Onion)
Tomato (Grosse Lisse)
Silver Beet (Giant Fordhook)
Lettuce (All seasons)
Basil (Sweet green, purple, curly leaf and Thai)
Rainbow Chard Parsley (Flat leaf and curly leaf)
Numerous tomato varieties (the only tomato variety that hasn't grown well was pineapple)
Yugoslavian watercress (also known as Lebanese watercress or Bulgarian watercress)
Chives (normal and garlic variety)
Chillies (many varieties, haven't found a variety that hasn't grown well yet) Celery
Kohl Rabi (Purple vienna)
Egg plant (Black beauty)
Capsicum (Californian wonder, Yolo wonder, Long sweet yellow)
Cucumber (Burpless, Armenian)
Dwarf beans (Butter beans)
Of course the plants you grow in your system may be limited by the type of aquaponics system you have, or more to the point, the type of plant growing system. If you have an NFT system you will not be growing carrots or large tomato plants because the small NFT pipes will not allow such growth. If designing your own aquaponic system you must put some thought into your plant growing method, and what you want to grow. This is one of the reason why we like deep media filled beds at Backyard Aquaponics, when you have deep media beds there are no limitations on growing different plants.
2. Different kinds of plants in Hawaii?
Please see above answer. This applies to native plants as well. So long as the nutrients that the plants require are in the system and the system is designed to support the plant structure it can be grown.
3. Is sprout production suitable for aquaponics?
Yes. Sprouts and wheat grass grow very well in aquaponics. System will just have to be slightly modified due to the way sprouts grow (placing a tray with seeds in the grow bed at a level they will get proper moisture for germination and growth).
4. How to grow and incorporate spiralina in the system for plant, fish and human food?
Personally I would buy some of these:
Free-Standing Conical Bottom Tanks
Their semiclear fiberglass construction allows 90% light transmission—perfect for algal culture. An integrated, skirted stand supports the tank and requires no assembly. Conical base slopes from 45° to 30° at bottom. An access port is cut out for the 2” NPT elbow located at the bottom of the tank.
Reinforced bottom and top edges prevent cracking and breakage. All tanks ship completely assembled and include 2” NPT bottom fittings. Special sizes available, please inquire.
I would not connect the algal culture tubes directly to my aquaponics system due to the fact that algae can affect water quality and clog pipes. I would inoculate the tubes with the spirulina culture and feed it using the sludge that comes from the aquaponics system.
Medium and Methods
1. What type of hydroponic production is better suited for aquaponics: NFT system, ebb-and flow with some kind of media, deep-water culture, aeroponics?
All of these hydroponic production designs are suited for aquaponics. The real question becomes what type of plant crops do you plan to raise, what kind of space do you have available, and the amount of finances you are willing to put into your system. Based on the answers to those questions you can select they type of hydroponic design you wish to incorporate in your aquaponic system. By the end of the course you should have a better knowledge of which design will best suit your needs.
2. I wonder how to duplicate the alchemy of soil in an aquaponics system?
I am confused by this question based on what the actual definition of alchemy is and based on what soil is actually composed of. Soil is made of air, water, mineral particles, organic matter, and organisms. Half of soil is pore space. Generally, pores are about half filled with water and half air, though the proportion varies greatly depending on weather, plant water use, and soil texture. Most of the solid portion of soil is mineral particles. Organic matter may make up only 5% to 10% of the volume of soil (less than 5% of the weight), but it is critical in holding soil particles together, storing nutrients, and feeding soil organisms (University of Minnesota; Extension). Different types of soil minerals hold and retain differing amounts of nutrients. Therefore, it is helpful to know the types of minerals that make up your soil so that you can predict the degree to which the soil can retain and supply nutrients to plants. Soil types can very greatly even in a small area of land this means that mineral contents and nutrient availability are not the same in all soil. This is why many soil farmers use either inorganic fertilizers or composted fertilizers to add to their soil to ensure it contains what plants need for growth. Aquaponics is the same concept. There is air (aeration system), water (for fish and plants), mineral particles (provided by fish feed and produced in the mineralization tank), organic matter (fish waste), and organisms (nitrifying bacteria, microorganisms, algae, and worms can be placed in grow beds). There is pore space in the flood and drain beds when water is drained from the grow bed as well as in the media (cinder, LECA), raft tanks and NFT systems have a pocket of air between the plants and the nutrient rich water.
3. Can cinder be used as the growing medium?
Yes, cinder is an excellent medium due to its low cost and abundant availability. The porous material allows more surface area for bacteria to grow on than gravel. The only issues we have had with cinder is that the plant roots are hard to detach from the cinder; larger grade of cinder will make for easier harvesting of plants.
Plant Health, Nutritional Needs and Quality
1. How many fish are required per plant?
In aquaponics the ratios are not decided by fish per plant. First the system should be designed with the starting point being either the amount of fish you want to produce or the amount of vegetables you want to produce. The key to designing a system is the feeding rate ratio, the weight of feed input to the system in grams per square meter of plant growing area per day. For the raft system the ratio varies from 60-100g/m2/day (based on type of plant crop being produced). Please read the publication from the Southern Regional Aquaculture Center entitled “Recirculating Aquaculture Tank Production Systems: Aquaponics – Integrating Fish and Plant Culture”. This gives the information with steps involved for designing a system from the perspective of the desired fish or plant production. It has the recommended component ratios for the different system designs including the flood and drain, NFT, and raft.
2. How to increase phosphorus, and potassium levels organically using organic local resources for high fruiting plants like tomatoes?
Phosphorus is not something that needs to be added to aquaponics. For fruiting plants it is recommended that you decrease nitrates (as they encourage vegetative growth). This can be done by allowing solids to remain in the filter tank for longer than normal so that denitrifying bacteria can break the nitrates down into nitrogen gas. Organic potassium supplements for aquaponics include rock potassium sulfate containing up to 50% K2O (potash) and soluble kelp powder can be used as well. Another important macro-mineral for fruiting plants that the system tends to lack is calcium. Most aquaponic producers use calcium hydroxide to supplement the calcium, this is not an organic form. An organic form of calcium would be calcium carbonate (coral is composed of this); this dissolves very slowly and cannot be relied on to maintain pH of 7.0. The last nutrient that is lacking in an aquaponic system is iron. This is because iron uptake is sensitive to pH. Chelated iron is used to supplement the system. If the chelating agent is a bunch of letters like EDDHA, DTPA or EDTA it's synthetic. Common organic chelating agents are lignosulfates and citric acid. The synthetics are far more effective but are not considered organic to growers.
3. How to know how much of each nutrient to add?
Iron is commonly supplemented into the system 1 to 2 times a month. Iron uptake is dependent on pH. If pH is at or below 7 only supplement 1 time a month, if you pH is above 7 supplementation should be 2 times a month. Dependent on the type of chelated iron you purchase there should be instructions on the package that say how much (grams or ounces) to add per square meter or square foot of soil. The same instructions apply to the grow beds. Add the iron in the same amount to your grow beds as you would soil. Calcium and potassium are added in the forms of calcium or potassium hydroxide in order to raise the pH which is lowered by the nitrification cycle; never add these to the fish tank directly as it will create “hot zones” momentarily (very high pH that would burn the gills). These are added whenever the pH of your system drops below the 7.0 range. According to Rakocy 2011 the practical way to determine how much calcium or potassium hydroxide you need is through trial and error. If the pH goes down rapidly, add more base until you maintain a pH of 7.0; try not to exceed 7.0 as some essential nutrients precipitate out of solution at higher pH levels.
4. How do you accurately gauge the amount of fertilizer needed to sustain plant growth?
In aquaponics there is not fertilize, just fish waste. Using the 60-100g/m2/day (based on type of plant crop being produced) of fish feed supplies the nutrients/vitamins/minerals required for plant growth. The only things that are lacking in aquaponics are Ca (calcium), K (potassium), and Fe (iron). These components are added as needed in the forms of calcium hydroxide, potassium hydroxide (both of which help raise the pH which is lowered by the nitrification process), and chelated iron.
5. What are common diseases of plants?
Some of the things that have affected the crops in our mini systems are powdery and downy mildew, aphids, whitefly, and leaf-miners. Other common diseases of crops in Hawaii can be found at http://www.ctahr.hawaii.edu/uhmg/conference/downloads/nelson-disease.pdf
6. Does fish disease have an effect on the plants?
Fish disease only affects plants if a majority of your fish are lost to the disease.
Fewer fish means less waste produced creating less nutrient availability to plants. I believe this question may be in reference to fish disease posing issues of food borne illness. Fish disease will not cause food borne illness in the plants. Any food borne illness caused would be due to secondary contamination of the fish or plants.
6. What is the nutritional value of food produced?
The nutritional value of food produced would be comparable to organically/conventionally produced food. Studies show that it is unclear if organic food is actually more nutritious than conventional foods but at least there is still no use of pesticides, herbicides, and fungicides on what is produced.
7. I wonder how does fish effluent supply both macro and micro nutrients for vegetable production?
Because the macro and micro nutrients are in the fish food. Fish need many of the same things that plants need for growth and development. Plants require 13 nutrients for growth and fish diets supply 10 of these in adequate amounts. The only thing that is lacking in the fish diets for the plants is calcium, potassium, and iron. Fish waste comes out in the form of ammonia most from the gills, this becomes the nitrates. The solids waste fish pass and also extra feed in the system contain the minerals. While solids are held in the filter tanks between cleanings, bacteria break down the organic matter and release inorganic nutrients (Rakocy 2011).
9. I wonder how does using the nutrients from the fish do to the flavor of the food?
Flavor of food produced in aquaponics is comparable to organically produced food. The nutrients provided by fish are in an organic form therefore they would taste much like organically farmed produce. Traditional farming and hydroponics uses inorganic fertilizer.
Physical System Operation Requirements and Components
1. What are the standard operating principles?
The Standard Operating Procedures are a set of guidelines on how to run an aquaponic system. This is to ensure all employees follow the same routine so that the margin for error during daily operation and maintenance is reduced.
2. Where on-island can I get supplies?
Taken from Aquaponics No Ka `Oi http://apnko.com/en/resources/where-to-get-stuff-on-maui
Al Badua, Haiku, 280-3180, Clarita@maui.net
-Live Chinese Catfish
Aquaponics No Ka `Oi, Kahului, 344-9756
-6' Wide Duraskrim R20ww 20 Mil LDPE White Liner From Raven Industries
-Live Tilapia fry, fingerlings, and full grown.
-Smaller quantities of 50lb bagged items.
Del's Feed and Farm Supply, 326 Hanamau St., Kahului, 873-0101
-Rubbermaid 100-300 Gallon and other Agricultural Tanks.
-Aquamax Fish Feed 50lb bags, some sizes are special order.
Down to Earth, 305 Dairy Rd Kahului, 877-2661
-Bulk organic seeds
Eco Products Maui, Kula, 878-6762
-Rain catchment systems, including 9’ and 12’ diameter X 44” deep tanks.
-Photovoltaic systems, including batteries and inverters.
Habitat for Humanity Re-store, 970 Lower Main St, Wailuku, 242-1140
-All kinds of parts for your aquaponics system, used, some new, at a great price.
(HGP) Hawaii Grower Products, Inc., 400 Lehuakona St., Kahului, 877-6636
-Vermiculite 6 cuft bags, coarse, OMRI Listed
-Chelated Iron (could be pricey, compare w/Waimanalo Feed on Oahu)
-Dipel DF (OMRI listed organic insecticide for caterpillars and worms)
-3/4" Cinder in 0.75 cubic foot bags
-Weedmat 12’ rolls.
-Net pots, tray flats, cell inserts. (good prices)
ISI Hawaii Water Solutions, 368 Lehuakona St., Kahului, 871-5459
-Large supply of PVC pipes, supplies, and irrigation parts. All sizes.
Joy of Worms, 9220 Kula Highway, Kula, 876-0911
-Red worms and worm composting supplies.
Ki-Hana Nursery, 1746A South Kihei Road, 879-1165
-Good quality weed mat in 3’ and 6’ rolls.
-Plumbing and irrigation parts.
Kihei Ace Hardware, Azeka Place Shopping Ctr, Kihei, 879-7060
-Benjamin Moore Paint
Kihei Gardens & Landscaping Co., Wailuku, 870-2940
-Gravel, red & black cinders, sand by the truckload.
Kula Hardware Nursery, 3100 Lower Kula Road, Kula, 876-0734
-Coir (Coconut fiber) 4.5 cuft block OMRI Listed
-Pacific Pearl Oystershell (Calcium Carbonate) 50lb bag
-Renee’s Garden Seeds
-Net pots and trays (may want to compare prices w/Ohana Greenhouse)
Maui Chemical And Paper Products, Inc., 875 Alua St # 101 Wailuku, 244-7311
-Produce bags & ties, fish bags.
-Paper towels and dispensers (for food safety)
Maui Feed and Farm Supplies, 495 Hukilike St, #7, Kahului, 871-1159
-Silver Cup Fish Feed 50lb bags.
Miyake Concrete Accessories, Inc., 250-N Waiehu Beach Road, Wailuku, 244-7988
-Blue Board Dow STYROFOAM™ Brand Square Edge Insulation Extruded Polystyrene.
(Special Order, make sure you get the Square Edge and NOT the SCOREBOARD)
-Rough construction materials incl. 2”X4” studs, plywood, metal stakes.
Ohana Greenhouse & Garden Supply, 320 Ho’ohana St., Ste. 13-16 , Kahului, 871-6393
Also, 810 Haiku Road #107, Haiku, 575-9999
-Hydroponics supplies, tubs, lights, pumps
-Net pots and seeding trays
-Seeds of Change
The Pet Shop, 70 East Kaahumanu Avenue (Maui Mall), Kahului, 877-3040
-Aragonite (Crushed coral for calcium carbonate).
-Aquarium supplies and water testing materials (may want to shop around for pricing)
Al Badua, (Live Tilapia, Chinese Catfish) Haiku, 280-6493, Clarita@maui.net.
All Roots Aquaponics (Nicholas Watson), (Live Tilapia) firstname.lastname@example.org, 250-2785.
Tracy Stice (Live Tilapia only at Maliko Gulch), 281-5411.
Aquaponics No Ka `Oi, (Live Tilapia), Kahului, 344-9756
PERMACULTURE AND AQUAPONICS CONSULTING/WORKSHOPS
Kaimanu Botanical Garden (Nick Oosterveen), Kihei, 250-5113,
Lanikai Farms (Lloyd Fischel), Haiku, 572-2269
1. What are the maintenance requirements?
We will provide you with a maintenance log for things that need observation and maintenance in your system.
1.a For the fish?
Feeding, monitoring water quality, observation of behavior, treatment in case of disease outbreak, and introduction into system and harvesting out of system.
1.b For the plants?
Feeding the fish appropriate amounts to ensure plants get needed level of nutrients, monitoring water quality, observation of health, observation for pest and disease issues, seeding, transplanting, harvesting, maintaining adequate lighting, humidity and ventilation.
1.c For the tanks?
Cleaning when needed; if there is a disease outbreak or lots of algae growth.
2. How is solid waste from the fish production removed or incorporated in an aquaponics system?
Many people use the solid waste on their soil crops or sell the solid waste to people who have soil crops they would like to use the waste on. We will be giving ours to the Master Gardeners at CTAHR to use on their crops.
2. What types of best management practices are established in dealing with the solid waste?
Most aquaponics producers remove the solid waste and use it as a fertilizer for soil crops they grow or sell it to those who have soil crops to be used as fertilizer.
3. How would I troubleshoot problems if they arise?
Ask for technical assistance or research for solutions. Many problems have arisen in aquaponics over the years and solutions have been developed. Issues that arise may be simple to solve or may require a process of elimination approach.
4. I wonder how I will be able to gather all the information to make a happy fulfillment of my system.
There are multiple aspects of the system to check each day in order to gather information needed to make sure the system is running properly. Most importantly is checking the water quality and ensuring that the parameters for bacteria, fish, and plants are met considering that the water is the supply of the environmental needs of these organism. Other important aspects are watching the behavior of the fish; changes in fish behavior are a sign that something is happening in the system. Observation of plants is also important, plant health can be used just as fish behavior, if the plants don’t look healthy then something is probably needing adjustment in the system. Also checking on the system is required, monitoring of flow rates is key in making sure that algae, debris, and fish solids are not clogging the pipes. The best way to keep track of this information is by filling compiling a list of items to be checked and recording daily the observations made.
Research and networking are key components in gathering information. This course will supply you with plenty of information to get started. However, things are forever changing and you may eventually want to expand upon this knowledge. The best way to do this is to read peer-reviewed articles (don’t base your decisions on random websites; peer-reviewed articles are science based and have been developed through extensive research projects and rigorous reviews from well-known scientists in the fields of study. Social network with those who are well-known in the industry. Reach out to Universities as well. Many people in this industry do what they do because they love it and are always willing to take time to inform those around them.
1. Can this system be used indoors, if good lighting is available?
Yes the micro system can be used indoors if proper lighting is provided to the plants.
2. What climates are beneficial to using aquaponics systems and which are not?
Tropical and subtropical climates are good for year round production without having to have a greenhouse. However these climates also have a variety of pests and disease issues. Temperate and cold climates can have year round production with a greenhouse. Cold climates may benefit from raising cold climate crops (trout is an example).
1. Covered, semi-covered, or open air set up?
This is dependent on personal needs. Obviously those in temperate climates need to have a covered facility for temperature control. Semi-covered would be good in areas with high wind and heavy rains. Open air is okay in tropical areas with low wind and rain. Fish tanks must always be covered no matter what to avoid algae growth.
2. Is there a way to create a system without purchasing an already made set-up?
Yes, but you need to make sure you know the science, plumbing, flow rates, engineering, aeration needs and ratios for size to create your own system.
3. Different kinds of structures you can use to build with?
People have used all types of structures to create aquaponics systems. Even old bath tubs as fish tanks. Just make sure the structures are safe to use with fish and plants that are planned for human consumption. Also be aware that there is a lot involved in constructing a system properly. It looks simple but there is a lot of science behind a properly functioning system.
4. What are differences between a fish production model and a plant production model?
* note from Christina -- not sure if they mean just physical system requirements or business model differences as well.
5. I wonder what kind of system would be a best match for me and my family needs?
This is dependent on the size of your family and the needs of your family. This is also dependent on the types of crops you will wish to produce, what space you have available, and how much money you can invest in your system. More information would be needed to properly answer this question and by the end of this course you should have enough information to answer this question for yourself.
6. How big do the ponds need to be to get commercially viable fish?
Your primary crop is your plants. I would be more concerned about deciding how many plants I would like to raise and then size my pond to meet the needs of the space in which I want to produce my plants. However, if you are wanting your fish to be the main crop just remember that you can have
0.5 lb/gallon so just figure how many fish you want to raise, what size they are going to get up to and then base the size of the tank/pond on that. Just remember for however large your fish tank/pond is you will have to dedicate the same amount of space (based on a 1:1) to plant production to ensure proper filtration of the water for the fish.
7. What are the main differences between a commercial and mini aquaponics system besides size?
The major difference is time requirements for maintenance. Mini system takes very minimal time whereas a commercial system is a full time job. Mini system is just for personal use; commercial system is a business. Mini system can’t raise food fish and commercial system can. The science is pretty much the same just on a much smaller scale in mini system. Very low economic risk on mini system whereas commercial system has much more risk.
Time & Resource Requirements
1. How much of my time is required to operate a system? Whether it be a simple backyard setup or a commercial business.
Backyard set-ups to small-scale commercials are about 4 hours a day. A commercial business is a full-time job that will require multiple employees that work part-time to full-time
2. How much money per household?
*need clarification on what this means; is this in reference to how much it costs to run the system or how much can a household bring in? This is all dependent on what you produce, how much you produce, and how well you market your product.
3. I wonder how much of my time this system will require each day?
Your microsystem will take about 1 hour a day to manage. The most time consuming part is the water quality testing which should be done daily when starting up your system to track the nitrification process or the nitrogen cycling. pH can be read automatically; high range pH (if needed) ammonia, nitrite, and nitrate tests all take 5 minutes to develop so water quality testing will take around 20 minutes each day. The fish need to be fed two times per day in 5 minute intervals (use this time to monitor your fish health and behavior) so this will be another 10 minutes. Other things that will take some time are plant observation and regular system maintenance. Time for this will vary from day to day dependent on if anything needs to be cleaned or changed (pump filter pad, tank, grow bed, LECA, etc.). A microsystem is ideal for busy full-time workers as it requires little time and maintenance.
A family-sized system to small commercial sized system will require 4 or more hours per day for one person to maintain. This system is more ideal for a family in which one member can devote a portion of the day to maintaining the system, i.e. stay at home moms or those who have a spouse who works part-time. Also involving children is a helpful resource in maintaining a family sized system.
A large-scale commercial sized system will require multiple employees working part-time to full-time shifts (and remember farming is a 24/7 job, these are living organisms and one must always be prepared for emergency situations, i.e. power outages). Also time must be devoted to harvesting, packaging, seeding, transplanting, marketing, inventory, and other such needs. A large-scale commercial farm best suits someone that is going to make it their full-time job or someone who can afford to hire full-time employees to manage the system.
1. Does the water have to be kept at a certain pH?
Yes. Water should be maintained at 7.0; this is a compromise between what the bacteria, plants, and fish all require.
2. Can bottled-water be used for the fish?
You can use bottled water but I wouldn’t recommend it because it’s expensive. Whatever you do DON’T use distilled water. This has had all the minerals taken out of it and fish need minerals in the water. I would just use county water from the tap and degas it by letting it sit for 24 hours. This water has minerals in it and is much less expensive than bottled water.
1. Is solar electricity used as part of powering the system?
Decide on the size and capacity you want in your solar panel; the configurations vary according to individual needs. Solar electricity can be used for water temperature regulation in the fish tanks; water temperature is important for health and growth of the fish crop. Solar power can be used for heaters or air conditioners to maintain the desired temperature in the greenhouse. Aquaponics uses low energy water pumps to move the water from the fish tank through a hydroponic componant. The low-pressure water pumps recycle the water for continuous use, and require a very small amount of electricity power which can be provided by a solar panel.
A large-scale commercial aquaponic system will require a large amount of power. You can save this expense and also conserve a significant amount of energy by converting to solar power. Solar panels are sturdy and long-lasting, so you can be assured of making a good investment. There are no emissions to worry about. Solar power adds to the organic appeal of aquaponics.
Largest drawback of solar power is the reliability on sunlight. Reliable operation of the solar system is dependent on investment in a backup battery system to store excess solar energy. This way, you will always have a supply of electricity for your needs. In case of an interrupted power supply, you may be at danger of losing your fish crop and also your plant crop.
2. Is small wind turbine able to power any part of the system?
Depends on how much wind you get and how many turbines you have but I am sure you could power the water pump or air blower depending on how big the system is. Just remember not only do you have to invest in the turbines but also in the invertors and batteries. Always be aware there must be constant energy provided to the system so always have a back-up power source connected to your system.
3. How do I troubleshoot the electrical needs of the system?
Water pump – water retention time in fish rearing tank should be 1 hour. Flow rate is calculated by dividing tank volume by 60 min. Example my tank is 1,000gallons/60min. Therefore I will need a pump that can move approximately 17 gallons of water per min. Based on this information I have to select a pump that can move this much water; volts/watts/amps per hour vary with size of pump. The more water a pump has to move the more electricity it is going to use. The smaller the system the smaller the pump and the cheaper the electrical costs.
Air blower-This is also dependent on the size of the system. As the system increases so will the horsepower (hp) of your blower. As a rough reference the UVI system has a 1.5 hp blower to operate 88 -6 inch air stones (22 air stones per tank – 4 tanks with the total water volume of the tanks being 8,240 gallons)
Pumping and aeration are what use the most electricity. However, a greenhouse will add to electrical cost when you factor in lighting, cold-storage, ventilation (fans), and computer/controller (for controlled environment).
1. How does the siphon system work?
§ As the water level rises in the grow-bed, water is forced through the teeth on the bottom of the bell and up between the walls of the standpipe and bell.
§ As the water level exceeds the height of the standpipe and the drain begins to fill, a siphon is created.
§ A majority of the water in the grow-bed is drained by the siphon until the water level reaches the height of the teeth.
§ Air is then forced through the bottom of the teeth, and as a result the siphon is broken, resulting in the grow-bed beginning to fill again; the cycle then repeats itself. (Fox et al. 2010)
a. See referenced article or read the how the bell siphon works paper that was included in the kit you were given
Level of Opportunity/Risk Involved
1. What type of realistic employment opportunities are out there for me after I graduate from this program?
As well as other career pathways in the agrascience natural resources realm
2. Will my spouse's fears be calmed that this is not another venture the I have become engaged in that won't bear fruit?
I am not a relationship therapist. I do not know your spouse and how fearful they are of this venture. I do not guarantee alleviation of pressure from them of your engagement in aquaponics. I can say that by educating your spouse on the benefits of aquaponics and the low energy, water usage, and space requirements along with polyculture production that it is a much more viable pathway of agriculture than traditional forms. There is also a high need in Hawaii for more aquaculture production and sustainability. As research continues in this area and it becomes a more used form of food production it will allow for more people to have access to less expensive supplies. Aquaculture itself is a fairly new industry and there are very few companies that offer supplies. Most fish farmers have converted wastewater treatment equipment into aquaculture equipment to lower costs. The good news is most of the costs in aquaculture are related to the need for expensive filtration equipment and aeration to maintain water quality for the fish; since the plants become the filtration this lowers investment because you can avoid having to buy filtration components. Water quality is keep fairly pristine in aquaponics and reduces the amount of aeration needed for the fish when compare to aquaculture.
3. Is it affordable for our communities?
Start up costs are always high but once the system is up and running it is profitable; I do believe it is affordable for Hawaiian communities due to having year round growing seasons without needing a greenhouse.
Rules & Regs
1. What rules and regulations apply to those who want to sell produce and/or fish from their systems?
Fish – If you sell the fish whole with no cuts then you are not required to build a packaging and processing facility that would also take a permit process. Selling fish whole is the cheapest and easiest way to get around having to be permitted for packaging and processing and avoiding have to build an additional facility. http://hawaii.gov/hdoa/adp/faq: Will I need a permit to get started in aquaculture?
Yes, permits of various kinds will be needed, for example, construction, digging a well, grading, etc. There are generally more land use and environmental permits required for projects near the ocean (along the coast), than operations located away from coastal areas. The State also offers the opportunity to be permitted to conduct offshore aquaculture in State marine waters. You may also need a permit to import non-native species into the state or to transfer a non-native species interisland. A special permit is needed to work with native species that are regulated by fisheries laws. Assistance is available from ADP to sort out the permit process.
State of Industry
1. What marketing networks currently exist for aquaponic products?
Currently I am not aware of any commercial production facilities that are selling to markets on Maui. I would assume that the same type of markets that are being tapped on the mainland and the other Hawaiian islands would be viable as marketing networks on Maui. Such markets would be;
Whole Foods and other health food stores
Costco and other franchises
CSA’s – community supported agriculture
2. How many commercial aquaponic farms are there on Maui?
It depends on your definition of commercial. Some people are bringing their produce to farmers markets but we are not aware of any aquaponics operations that are solely focused on producing for profit.
3. Are there any SUCCESSFUL commercial aquaponic farms on Maui? What has made them successful?
General/The Bigger Picture
1. How do we make it as simple as possible to share it effectively with others in our community?
2. I wonder how we get aquaponics practitioners on board with standard operating procedures without stifling innovation?
3. Is it practical for the everyday person?
A small system is practical for the everyday person. Larger systems require more attention and are most likely not practical for the everyday person who works a full-time job, unless that person is very good at time management and can allow for about 4 hours a day to manage the system; this person would also have to find someone to maintain the system if they were to go on vacation or be gone for periods of time.
4. Will others share this passion?
Many people share this passion. Fish farmers, hydroponic growers, organic food producers, renewable energy representatives, and those who want to create sustainable agriculture all are interested in what aquaponics has to offer. Teachers also appreciate aquaponics as an educational tool that keeps the students interested in multiple subject areas. Interest is greatly increasing as commercial systems are showing more success as the systems are being refined.
5. How do I bring what I see as sustainable resource to Lanai, to slow the reliance on weekly barge dependence and reduce a portion of the of oil dependence?
Education and outreach is key for informing the public of the importance of sustainability.
6. I wonder what would benefit the population the most – effective local food production or import – the general public should get enlightened.
Currently agriculture is at a crossroads in Hawaii. Hawaii imports between 85-90% of the food its citizens consume (Leung and Loke 2008). Food safety scares and increased cost of oil have amplified the general public, businesses, and government leaders of the state of Hawaii’s concern for energy and food self-sufficiency (Leung and Loke 2008). Farm production fluctuations on the U.S. mainland and dock strikes leave Hawaiians vulnerable to food supply disruptions (Leung and Loke 2008). There is now a competitive need for local food production to replace imports due to increases in fuel price causing increase in freight transportation. Sandra Lee Kunimoto, chairperson of the Hawai‘i Board of Agriculture, summarized the benefits of “buying local”: “Purchasing locally grown produce keeps the money flowing through our community. When you purchase foods grown elsewhere, you are supporting agribusinesses in other areas. Also, the nutritional content of locally grown foods is often higher, since many vegetables begin to lose their nutritional value after they are picked.” (The Honolulu Advertiser, August 14, 2008). Local consumption of food also conserves energy and reduces Hawaii’s carbon footprint. The importation of fresh produce into Hawaii risks bringing in invasive pests (Leung and Loke 2008). Replacing just 10% of the food we currently import would amount to approximately $313 million. Assuming a 30% farm share, $94 million would be realized at the farm-gate, which would generate an economy-wide impact of an additional $188 million in sales, $47 million in earnings, $6 million in state tax revenues, and more than 2,300 jobs (Leung and Loke 2008).
The Constitution of the State of Hawaii, Article XI, Section 3, says, “The State shall conserve and protect agricultural lands, promote diversified agriculture, increase agricultural self-sufficiency and assure the availability of agriculturally suitable lands.” Food self-sufficiency in Hawai‘I is dependent on sound public policies, the best available science, an efficient industry, and a public willing to support local agriculture (HDOA 2008). Locally grown foods have direct and indirect benefits for the state. Direct benefits include increased local production of food and self-sufficiency, reduced independence on imports, diversified economy, stimulation of local economy, decreased vulnerability to food supply disruptions, reduced risk of importation of invasive species, decreased carbon footprint, promotion of healthier lifestyles and nutrition, preservation of Hawaiian farmland, and agri-tourism support (HDOA 2008).
Efforts must be made to support farming in Hawaii. Maximum use of land, water, and energy is keep to the success of self-sufficiency. Another important factor is the need for new farmers and agricultural workers. The age of the average farmer in Hawaii is 59 years. Therefore, to increase interest in farming and create new farmers there should be a development of educational programs that encourage career paths in agriculture (HDOA 2008). This is a critical time for agriculture in Hawai‘i. Hawai‘i risks losing prime agricultural land, water systems, and farmers, which will diminish the state’s ability to increase the production of locally grown food (HDOA 2008).
Hawaii isn’t the only place in the world suffering from food insecurity issues. According to Rakocy (1999a) local conditions justified construction of an aquaponic system developed at the University of the Virgin Islands more than 30 years ago. The Virgin Islands lack sufficient freshwater for pond culture, and most of the fish and vegetables consumed there are imported at extremely high costs. Due to the limited sources and adverse climatic conditions in Saudi Arabia freshwater is an expensive commodity (Al-Hafedh et al. 2008). There is an increasing demand in Saudi Arabia for fresh fish, but due to the expensive nature of freshwater, the development of aquaculture is slow. This makes the theoretical background for aquaponics in Saudi Arabia similar to that of the Virgin Islands. Further expansion of aquaculture in Saudi Arabia depends on the application of new technologies to intensify fish culture and to maximize water re-use (Al-Hafedh et al. 2008). Aquaponics systems are ideal in areas where soil is very poor (Hughey 2005).
Importation, lack of freshwater sources, exhausted soil, depletion of fossil fuels, and climate change are not the only reasons that aquaponics is beneficial. Aquaponics could assist in the alleviation of limitations that the local seafood industry faces. The most major limitation being that some waters are extremely overfished and humans still consume the overfished species as if they are not depleting in nature. This means that the existing demand for local fish is not being met sustainably (Roche 2011). Marine fish can’t be raised in a freshwater aquaponic system but species such as tilapia can. While tilapia is not a Cod or Haddock it is a similar light white fish (Roche 2011). Replacement of tilapia over native fish species for meals would give wild populations a chance to regenerate themselves. The aquaponically farmed tilapias have higher levels of Omega-3 fatty acids than the Atlantic Cod and Haddock (Roche 2011). The tilapias also have much lower mercury content than marine fish species. The tilapias are also less costly than marine species and aquaponics allows year-round production giving them a consistent price throughout the year. This is not true for wild species whose prices fluctuate with season and weather (Roche 2011).
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