been taking a brake from this site for health reasons, but I see some little problems have'nt gone away.
ok here goes
your tank is well over stocked and WRONG
15 gal
2 rummynose tetras............ need to be in at least groups of 4
1 serpae tetra................. same as abouth
1 x ray tetra......................same as
3 male guppys..................not realy a prob apart from the fact they can be fin nipped
a male platy..................... ok but your over stocked
1 flying fox........................ will grow about 6 inchs, and is to big for your tank
1 peltobagrus ornatus..........I have to admite I don't know what on earth this fish is
4 neons..............................Ok but your over stocked
2 glowlight tetras.................. need to be in groups of 4
I don't know your inch's off the top of my head, will post when I get my book out.