Number Of Crayfish In Tank

Hi! I have 2 small crayfish in a 20 gallon tank with tropical fish and they a co-existing well. However, I'm afraid that once they get larger, they will want to eat the fish. So I'm thinking of putting the crayfish in a 10 gallon tank and possibly getting some more crayfish. What I am wondering is if anyone knows how many small/medium crayfish I can have in a 10 gallon tank without overcrowding it. Thanks!

 

Those small crayfish will grow to be big crayfish. Like i said before these things are mean! My friend has one in his african tank and his took down a african, it was small but still. I used to feed mine feeder fish. (i caught mine in the river down the road)

 

like m_wn said, the crayfish will take out the fish.....how do you think they ear in the wild? they catch small live fish, but also feed on other decaying matters