I'm a newbie to fish keeping and purchased at 20G for glow fish because I thought they looked cool. I got some good info from lfs about NTS, cycled 20G 8wks added 2-3 glow fish at a time over several weeks. Fast forward 2 months and I wanted fancy guppies. Rep at petsmart said 5 male fancy guppies can go in 20G w/ 8 glow fish. After I bought said fish I was still in-store same rep tracked me down and said guppies are more picky about water qual+temp then glow fish. I was afraid guppies would struggle so rep steered me to a 5.5g to keep them in once cycled. Did more research at home after purch, found out 5.5g too small. I'm at a loss, guppies are still in 20g I was going to move them to the 5.5g when cycled but if its too small can the guppies survive in the 20g until I can buy a larger maybe 55g around Black Friday this year? I will then make the 55g a guppy tank, keep the 20g glow fish tank and does anyone have suggestions on what I could do with a 5.5g??? I would prefer something other than a Betta.