My sister purchased a 10 gallon tank but doesn't know what can thrive in it. She likes the colors of neon tetras and guppies, but are those really ok for a 10 gallon? What species (example: guppies and neon tetras) could both go together in the tank?

Do any of the fish require less maintenance than others? Which fish are good for beginners? Thanks!

OH! And also:
When she gets her fish, can she feed them goldfish food or betta food?

You might wanna go for guppies or platies first since neons are rather delicate and sensitive about the water quality. Does she have a heater for the tank?

For a ten gallon you could divide the tank and have bettas. Or you could have a few guppies and platies, just make sure you either get all females or all males. Or a school of either glowlight or x ray tetras since these are less demanding. For the bottom you can have three cories, or a few ghost shrimps. These are very good at scavenging.

I think you can feed them betta food since they ussually contain the same thing as tropical flakes. Just make sure you supplement with other meaty foods and veggies. Good luck.

Yep yep, she has a heater. I'll talk to her about guppies and platys. Thanks for the reply!