Anyone who has taken a serious look into fish farming and hydroponic gardening knows that although they pose some great food yielding and even ecological potential, they’ve got some significant negative environmental impact issues that some may not find favourable. These issues include the further depletion of wild fish stocks due to fish food production for cultivated stocks, the flushing out of chemical nutrients and other undesirable water contaminants when hydroponic systems need to be changed and refilled and the wastes produced by farmed fish that necessitate disposal and expensive filtration measures and/or use of chemicals.
However, aquaponics may very well be the environmentally friendly future of both conventional hydroponic systems as well as traditional aquaculture fish farming. Fish farming produces fish waste and ammonia that’s released in the aquaculture tanks when fish ‘exhale’ through their gills. Normally this requires special filtration equipment and chemicals to keep water conditions clean and suitable for a high density of fish. In hydroponics, although only a fraction of the water is needed for crops as compared with soil based agriculture, the left over mineral nutrient solution that needs to be changed about once a week, is sent down the drain into local water ways and still becomes a contributor to water pollution.
Aquaponics fish farming however, solves all of these problems by marrying the needs of hydroponic gardening to the needs of aquaculture fish farming. The wastes produced by fish break down into nitrites that special bacteria break down into the rich nitrates that form a much more complete source of nutrition for the hydroponics plants. As the water from the fish tanks are fed to the plants, their roots clean the water by taking up all the contaminants (that would otherwise kill the fish) in a near closed loop system.
Fish feed is typically made from wild fish that harvested from already depleted oceanic fish stocks, making aquaculture fish farming environmentally controversial, however there are sustainable forms of fish feed that allow growing fish for food to be an environmentally friendly venture. Growing fish food on your own for example isn’t as difficult as one may think as it can simply consist of raising bug larvae off crop cuttings and then feeding the larvae to your fish stocks.
As for your fish farm equipment you want to be sure that you have the following back ups in place in case of problems. Power failures can quickly lead to disaster and death in both your crops and your fish stocks. To avoid this problem, you want to have the kind of water and air pumps that include built in/rechargeable back up batteries so they continue to work during power outages and simply recharge once power has returned. These kind of back ups should also be set up to automatically turn on in case you are not around when the power outage occurs. Another alternative is to have a separate, automatic back up power generator for your whole system. If you’re keeping tropical, warm water loving fish species and you live in an area that gets cold you may want to invest in a water heater because if the temperature drops lower than what your fish can tolerate they can go belly up fairly quickly.
The only other input you’ll need for your aquaponic fish farming is additional water as it evaporates from your system naturally, some chelated iron and the occasional (once a year) fish friendly, liquid seaweed extract nutrient boost for your hydroponic garden should there be any evidence of deficiencies in your plants.