Went into a pet shop before, they have just been taken over by a new guy, he asked me what tanks i had and he told me this little 5 gallon i have could have 30 fish in!
Don't go there ever again, he's in it to make a bit of money and won't care about the welfare of the fish. What fish did he say you could have in this 5G? Fry?
I went in there for plants for my 20g and i told him i didn't know what i was going to do with my 5g. He said a good filter will let you have 20-30 fish! I just agreed and walked out.