new Corydoras only tank

[platytudes]

I don't think guppies would keep to the top very much. They're sort of midlevel...if you are keeping it cool for them (high 60s, low 70s) then you might try some bloodfin tetras or danios of some sort, pearls are the prettiest IMO of the common pet store variety but I know there are much nicer ones such as D. choprai or D. roseus.

Oh and by the way, love your tank! Adorable little cats

 

[lookit]

If you want top dwellers, common hatchets would be perfect. But you've got to remember that they're olympic jumpers, so you have to be very watchful of the tank top during water changes.