Unless you have a rather large aquarium, I'd suggest you do not try to keep this fish. It can get to about a foot in the aquarium. Also, this fish eats live foods, so if you're squeamish about feeding your fish live prey, then don't get this fish...also, you'll have to be either raising his food yourself [and I don't mean brine shrimp] or running to the lfs quite often [feeder goldfish are common food in the aquarium for this fish]. All your fish in the tank will have to be larger size---meaning bigger than the grouper's mouth, otherwise, they will be potential prey for the fish.