“Aquaponics, the cultivation of fish and plants together in an constructed ecosystem utilizing natural bacterial cycles to convert fish wastes to plant nutrients.
This is a re-circulating culture method harnessing the best attributes of aquaculture and hydroponics without the need to discard any water or filtrate or use and change out chemical fertilizers.”
Aquaponics is a Natural way to grow food without the worry of toxic herbicides, pesticides or fertilizers since those things would harm the fish and bacteria. Biological and mechanical pest control are practiced in Aquaponics.
By adding plants to a recirculating aquaculture set up (or even an aquarium) one can reduce or eliminate the need to change water because the nutrients are now resources for the plants rather than pollution for the fish. And by using fish waste as the nutrient source, the hydroponic portion avoids having to buy costly chemical fertilizer mixes to grow plants.
There are many types of Aquaponics systems out there though the most widely used are Raft Bed (DWC, deep water culture) and Media Bed (gravel bed). There are also NFT systems (Nutrient Film Technique), Vertical systems, tower systems, and Combination systems.
The key elements that must be addressed for each aquaponics system design include;
1-a place with adequate water, circulation and aeration for the fish (or other Aquatic animals.)
2-a place with adequate support, water, nutrients, and aeration for the plants
3-a place with adequate surface area, water, aeration and dark for the bio-filter bacteria
4-some means of adequate solids filtration that will not deplete the rest of the system of dissolved oxygen or cause the build up of negative compounds.
How to manage 1-3 is usually rather easy, number 4 seems the most hotly contested topic in aquaponics today.
Some Basic Rules of Thumb for setting up a new Flood and Drain Media bed Aquaponics System Design include;
a-Plan on at least 5-10 gallons of fish tank per grown out fish.
b-At least 1 cubic foot (about 7.5 gallons) of grow bed per pound of grown out fish.
c-Pump or circulate the volume of the fish tank at least once an hour.
d-additional aeration or circulation should be provided all the time. If the pump does not run all the time spraying water into the fish tank, an air pump or additional small circulation pump can take care of this.
e-always use big enough plumbing for the pump.
f-Gravity drain plumbing must always be much larger than the pumped plumbing feeding the container. (if the plumbing from the pump to a Tank is a pressurized unrestricted 1″, then make the drain plumbing 2″ or even 3″.)
g-Always install overflows lower than you think you want them, it is easy to use plumbing to make them effectively higher but if they are too high, it requires another hole to make it lower.
h-Plumb in a bypass. Put a T on the feed out of the pump and send part of it with a valve back into the same tank the pump is in. If for some reason the flow from the pump is too much, open the valve to bypass some of the flow back into the same than the pump draws from. This allows one to restrict the flow into a tank or bed without straining the pump and the extra flow splashing back into the tank just provides extra aeration.
I-Run initial tests on the source water and remember that the water must be allowed to air before the pH tests will be accurate.
J-I highly recommend Fishless Cycling.
Following are some links to more in depth details for designing your own aquaponics systems;
Basic Aquaponics System Media Bed Design Rules of thumb