Ok, I have 20 baby fish in tank 1, 10 fish in tank 2, and 5 pregnant fish in the selling tank. Can you not have 60 fish at a time, in the three tanks? I thought the max in each was 20. Has anyone had 20 fish in each? Also, can you only do one research at a time? I don't have enough money to try.

you can only research one level of a category at a time, however you may research more than one category at a time, if i remember correctly

and you should be able to have 20 fish per tank, i almost always have that

check to make sure there are no dead fish in the tanks, they take up a space, same as a live fish