Choosing appropriate fish
Hopefully, you’re doing or have done a fishless cycle, you know the pH and hardness of your tap water and you’re ready to start stocking your aquarium.
How many fish can your aquarium accommodate?
Firstly, the number of fish you can keep in a tank is affected by quite a few variables. Obviously the volume of water has an effect on stocking capacity as do the tank footprint and the species’ that interest you.
You’ve probably heard this golden oldie stocking rule of 1 inch of fish per gallon of water or its updated equivalent of 1 cm of fish per litre of water. Unfortunately,that only works in a very limited way ….it only takes a minute’s thought to realise how flawed this “rule” is. Fish body shapes vary drastically and two fish of the same length may have entirely different height and girth. Some species’ produce more waste than others even if they are the same length. For example, compare the body shapes of a 12cm long Kuhli loach to a 12 cm long Angelfish. The Angelfish is almost as tall as it is long and it will need more water volume, more filtration and more physical space than the Kuhli. Yet the 1 cm per litre “rule” would say you could keep four in a tiny 50 litre tank.