Sweetange
Well you also have to remember the rule: One inch per gallon
When buying a fish at any pet stores, make sure they are healthy with no visible diseases
Depending on what the fish, some have shorter lifespans than others like the guppy.
Before adding fish to a new aquarium, the filter must have been running for at least a week


the one inch per gallon doesn't work for every fish, because different fish have different needs. you cant keep a 24inch oscar in a 24 gallon tank, it wouldn't be able to move. and you cant keep any type of goldfish at any length in any tank under 25-30 gallons and that's for one fish but their social so they really need at least on companion, oh look that means 55 gallons!

you really should do research on every type of fish you get before you get it (and look at multiple sources, not just pet store care sheets)

I really recommend Fishprofiles.com , or Ultimatebettas.com