LiveMermaid07
Bloody Mary. As in, hand me one.
For the filter, I am using a DIY sponge filter. The heating I am not so sure about right now. I will probably go out and buy a heater that is made for mini aquariums.
I have one of these, the 25watt topfin heater overheats it so I don't recommend that.
Just a thought, at the dollar tree they have these foam boards (the size of poster board) the thickness is the same height as the 'feet' on this tank, I cut out a piece just narrower than the feet and rolled a piece of packing tape and stuck it on the bottom - after covering the whole board with packing tape to waterproof it just in case. That way it should spread the weight on more than just those tiny feet. Since the shelf it's on has a bump on one side I also cut a piece that was a bit bigger than the bottom - wrapped it with tape - and set the whole thing on that. The bump still tilts it a little but I think that's cause the tape made the foam less bendy lol.
My first vote would be for the cherry tank, but you said you already have that, so my second vote is Betta, and my third vote goes to those cute little frogs in Jannika's post.

Filters I have used on this size, sponge filters, tom's internal filter, aquatech 5-15 (cut the length of intake). Could also easily make a diy undergravel filter for one of these.
The 15watt T-5 bulb had the most vigorous plant growth, when that blew I cobbled a dodad for a 13watt cfl, that one works ok, but they way I've got it the front doesn't get much light.