Its already almost 6 inches long. she has it in a 20 gallon tank. she said she cant afford a bigger tank and hates that he is in such a cramped space. im a sucker for fish so i might take it. but will a fish that size disrupt the eco in my 55 gallon? i already have 2 plecos. one is rubberlipped and only 2 inches, the other is chocolate and is about 4 inches.