I have 3 glass (ghost) catfish in my 30 gallon (my local store recommended groups of 3). I have been reading online and have found that they do better in groups of 5 or more, they behave fairly normally now (they aren't in a school all the time but they are fairly full grown, I figure they get more adventurous as they get older), but I wondered if they would prefer to have a larger school. Any suggestions?