Fish are an important part in making this process work . Another aquaponic secret is that the plants you choose to grow require nitrogen, and that’s great because the fish provide this with elimination of both urine and feces. No matter what system you decide to build, these nitrates must be cleaned from the water or the aquaponics fish will die. An aquaponics fish tank requires filtering systems that must be either cleaned or replaced on a regular schedule. The grow beds of the aquaponics system act as this filter without the hassle of cleaning the fish tank making this another reason why we call it easy aquaponics. Plants and fish must be present in this system for The Nitrogen Cycle to take place.
Almost any freshwater fish can be raised in the system although the operating temperature prohibits rearing of species such as trout. If you do not care about either eating or selling the fish we recommend using half of the fish as goldfish and the other half as common carp. One fish per 1.5 gallon water is the maximum a system can handle especially as the fish grow larger. Goldfish and common carp can be bought cheaply at bait stores in most parts of the country.
Recommended Aquaponics Fish Species
|Walleye||Tilapia||Yellow Perch||Lake Perch|
|Channel Catfish||Bluegill||Hybrid Striped Bass||Northern Crayfish|
|Largemouth Bass||Smallmouth Bass||All Carp||Goldfish|
|Koi||Most Freshwater Ornamentals|
Aquaponics Fish Food
Raising fish means you need to feed your fish. You can buy fish food pellets or organic fish foods to keep everything organic, however, this can cost over time. There are a few systems for creating fish food. Another one of the aquaponic secrets is that you can raise fish food that doubles itself every 24 hours under correct conditions. This is a great money saver and fits in with doing less work is more.
You can raise duckweed in 55 gallon barrel halves. The water temperature needs to be 60-70 degrees F. and rich in nutrients. We get these nutrients from manure tea made from donkey dung. Fish eat duckweed slower than commercial feeds so we feed at the first of the day and if all is eaten by dark then we add a little more. If there is duckweed left over from the night before then we simply feed Duckweed Floating on top of Manure Tea less.
The nice thing about duckweed is that it just floats around and too much does not constitute nitrate buildup like with uneaten commercial pellets. Eventually it will be eaten and, meanwhile, it is making more duckweed. In nature, duckweed can be found floating in calm waters, either fresh or brackish. Virtually all the plant is metabolically active and totally useful as a feed or food. Duckweed has high concentrations of essential amino acids, lysine, methionine, carotene, xanthophylls and trace minerals making it one of the best animal feeds available for either fish or animals like rabbits, sheep, goats or cattle. It can be fed wet or dried without significant loss of nutrients.
Nitrogen Ammonium is the preferred form of food for duckweed. This is fortunate for us as the aquaponic system produces an abundance of this material. Therefore duck-weed does great in such systems except for trace minerals Duckweed growing in half barrel which because of the soil-less nature in aquaponics, are sadly lacking. This factor can be solved as it exists for not only the duckweed but both the plants and fish as well.