goose_uk;1447637; said:General rule for fish tank size - the width should be 1 1/2 times the length of an Adult fish for the fish to reach full potential size.... It is to to do with the fish having the correct amount of turning space.
This is a general rule and there are exceptions, and no doubt I will get flamed by people who are keeping those exceptions.....!!
But hey.....
Stunting is based on the volume of water the fish is kept in, not the width of the tank. This might be incorrect but I have heard that growing fish release a growth inhibiting hormone (the purpose of this in nature is beyond me) that is diluted in large bodies of water (lakes, rivers, etc.). In the aquarium, no matter what size tank you have, this hormone builds up. Obviously it will build up faster in a smaller tank, but even with a large aquarium you need water changes to remove this hormone. You could keep an oscar or a red devil or what ever in a 200 gallon tank, but if you never changed the water, it would grow slower than a similar fish in a 75g with weekly water changes.
