I have two planted five gallons on my desk at work. One has pygmy chain sword, rotala, moneywort, a banana plant and java moss with two african dwarf frogs, one honey sunset gourami and three dwarf platies in it.
The other has pygmy chain sword, red ludwigia, moneywort, rotala and java moss. It has a few ghost shrimp and four neons in it.
Both have a selection of MTS and ramshorns.
Thus far (about 8-10 months) the platy's have not bred, or have bred but eaten all the young. I have two that are small and slim and one that is much larger and very fat, so I'm thinking I definitely have a male/female mix. They should have been pumping out babies, but fortunately have not.
I had guppies when I first set up a tank a few years ago. The two turned into about 300 in the space of a few weeks. You DON'T want that grief in a 5 gallon. Therefore, stay away from livebearers, even platys.
Neons are great little fish, but fragile. I've tried a few times to bump up my four to a larger school, which they need. Every time I've tried though, I've managed to bring in a disease that kills off all but four of the neons. This is mainly because I'm a dope without a quarantine tank.
Neons, however, do work well in this size tank. I'd say 6-8 would be a good number. It sounds like a lot of fish for the tank, but they are small, clean, and do require numbers to be happy/healthy. If you don't, they sit in the corner and never move. Harlequin rasboras may be good too, but I've never kept them so I have no experience to draw on.
If you choose neons, you MUST have a bottom feeder of some sort. They will not eat anything that lands on the substrate. This makes feeding hard, because they don't catch a lot of what starts to sink when you feed them.
Mix them with shrimp, snails, or a few very small bottom feeders. Pygmy cories are great, but they also require numbers to be happy. Such is the curse of five gallon tanks.
Hope it helps!
