I have 2 delhezi bichirs at 4 inches. Do you think the 20 gallon is too small? I was told a 40 breeder would be better. The size of food they can eat is literally crumb size and I was thinking it would be hard for them to find them in a 40 breeder. I am trying to get a 40 for when they grow medium size and after that, at least a 75 gallon when they reach nearly full size. Should I try to get them into a 40 asap?