Stocking your FishPlant fish tank
Your FishPlant Family Unit should be stocked gradually, allowing the system to develop in harmony with the fish biomass. A target biomass should be about 3kg of fish (about 1kg per 100 litres of water), with a maximum of 3.5kg. You should put in a small number of fish at regular intervals, so that by the time the first fish are at a size fit to eat, you are at or about your maximum biomass.
So, for example with Tilapia we might stock 5 fish every 6 weeks, with an average start weight of 20g and a minimum harvest weight of 350g. By six months, under ideal temperatures, the biomass might have reached 3.5kg and 20 fish, working on average weights of the fish. As with all living things some would grow faster than others so you may be able to harvest the first fish at about 5 months.
From this point on you should be able to harvest 5 fish every six weeks so the biomass will fluctuate between 3 and 3.5kg. With some slower growing cold-water species, you may have to plan the stocking programme over 12 months.
When stocking fish it is extremely important that the temperature of the culture water is similar to that in which the fish arrive. A temperature difference of greater than 2 degrees in 1 hour, will shock the fish, potentially fatally. Place the bags containing your new fish inside the fish tank to allow the water temperature to adjust gradually before opening the bags, gradually mixing the water and then finally releasing your fish into the tank.
During their first 48hrs in the tank, closely monitor the fish and avoid causing any unnecessary stress. To start with, avoid feeding the fish, however after a few hours introduce a few pellets and observe their feeding behavior. For the next 48hrs, continue to feed the fish sparingly, and only if they are eating all the food within a minute or so of it entering the tank.