6 neon tetras 3 platys/mollies (dont know which) 4 serpae tetras 2 tiger barbs obviously in a 20 im gonna be reachin my limits real soon if i get more tiger barbs..and when they get older im screwed. so im thinking about getting a 40 gallon. 50-55 is a bit too much space wise for me right now. but theres an ad on craigslist for a 40 gallon BREEDER tank, which comes with everythig i need except water and fish for 50 bucks..i dont know if i should jump on this or not cause i dont know if itll be that big of a difference for the fish and the space ill have? a 40 gallon breeder is only about 12 inches longer than my 20 gallon, and itll be 6 inches wider. however a 40 gallon long is like 20-24 inches longer than a 20 gallon, but theres none on craigslist currently. would the 40 g breeder be alright? or is it a waste of time? cause i know these types of fish need swim room, and i feel like they wont get much swim room if its not length wise? i'd plan on getting a handful more of each species of fish that i already have (besides the plat/mol) and maybe get a blue ram in there too.