Residential fish farming, as the name suggests is the small scale production of consumable fish from the comfort of our house. This concept has grown widely in recent years owing to its ease and the surplus produce. The fact that fish available in the market is preserved for over 2 months generally, before reaching the consumer. Preservatives like ammonia is used(in Kerala) to avoid deterioration of the fish over time and to store at higher temperatures. These preservatives have a very adverse effect on our health.
Residential fish farming thus proves a solution to the increasing costs of the fish as well as the adverse effects that may arise due to consumption of chemically treated fish. In addition to all these, there exists the following advantages:
Inexpensive to run
Easy care – all you need to do is feed your fish!
any size and shape ponds can be made
highly productive methods can be practiced
takes very less time
Can be integrated with growing vegetables- Concept of Aquaponics
Residential fish farming thus proves a solution to the increasing costs of the fish as well as the adverse effects that may arise due to consumption of chemically treated fish. In addition to all these, there exists the following advantages:
How do we start?
I have been doing residential fish farming for quite some time now just as a hobby. I had converted a 3*3m rainwater storage tank into a fish tank. Setting up a cement tank just for growing fish is absolutely a loss. Instead, fish can be grown by digging a small pond and using tarpaulin sheets over it to avoid loss of water. A point to be noted is that before laying the tarpaulin sheets, lay enough empty cement bags(easily available from any construction sites) or coconut shells etc. to avoid roots of trees from making holes in the tarpaulin sheets leading to leakage of water. Another alternative to digging up a pond is to lay some cement bricks in form of a rectangle and laying tarpaulin in between to obtain a small water reservoir enough to grow fish. Here again, precaution against roots should be taken.
Aquaponics
Aquaponics refers to any system that combines conventional aquaculture (raising fish,prawns etc in tanks) with hydroponics (cultivating plants in water) in a symbiotic environment. In normal aquaculture, excretions from the animals being raised can accumulate in the water, increasing toxicity. In an aquaponic system, water from an aquaculture system is fed to a hydroponic system where the by-products are broken down by nitrification bacteria into nitrates and nitrites, which are utilized by the plants as nutrients, and the water is then recirculated back to the aquaculture system.
This system wherein the water is recirculated after filtering through the hydroponic system may seem to be complex. An alternative to this is to pump the water from the bottom of the tank(or tarpaulin sheet where fish is grown) such that the excretions are pumped out to the place where vegetables are grown. This can be done only when the plants are required to be watered. Fresh water can be pumped into the tank to compensate for the pumped-out water. Hybridizing aquaculture and vegetable cultivation is very beneficial as the water from the tanks are rich in nutrients and thus, is a natural manure.
Which Fish Do we grow?
The most important factor in residential fish farming is to select which fish breed has to be grown to obtain optimum output. There are a few options I would choose:
- Tilapia and giant gourami is a good option. Tilapia is a fish that is widely produced. It is an over-powering fish which doesnt consume other fish. Tilapia grows fully in around 6 to 9 months weighing from 600 grams(normal tilapia) to 2.5kilograms((ailotica(broiler) tilapia) depending on the feed provided. It also reproduces largely. Giant gourami can also be grown along with tilapia without harm. It grows upto 6 kg.
- Another alternative is to grow breeds like cutla, rohu, mrigal etc. which can grow together. These grow to very large sizes(like 80 kg size) if they are introduced to natural ecosystems but in small ponds and tanks the sizes can largely differ.
Building an ecosystem
It is essential to build a good ecosystem in order to ensure sufficient growth of the fish. Fishes that breed quickly has to be provided with breeder colonies so that external disturbances does not affect reproduction. Generally, to avoid loss of fish seed, males and females are introduced into a temporary pond generally in the ratio 1:4(one male for four females). This is done mainly in case of Tilapia. If allowed to breed in the same tank, there is high chance that the fish seed gets eaten up by the other fishes or tilapia males.
Setting up a breeder colony is easy. Accumulate sand, soil, stones etc towards one end of the tank (or tarpaulin sheet). Also introduce pieces of PVC pipes of various sizes near the stones. This is done to allow the females to hide once the eggs are fertilized.
