Looking good Liz
Not sure how big you want to go re: tank, painteds don't get as big as the various sliders that people keep around here, you could probably get away with something like a 40BR for 2. I kept a trio of painteds in a tank that was somewhere in the 65G range, the footprint was around 40"x20" and they did just fine. In that setup I ran a fluval 404 and it kept things very clean, and I used large (2" or so) river rocks for substrate because I hate the look of bare bottom. Their basking platform was actually a couple of flat rocks on top of a milk crate, the crate was on its side so the turtles could swim under the platform and didn't lose any tank space. You'll want them to get UVB either via a temporary outdoor pool (that's what I do with my baby turts but I'm in Florida now and can take advantage of the nice weather) or a UVB tube like the ZooMed iguana lights.
What are they eating? Painteds are pretty largely carnivorous, especially as babies, so best bet is to get them on a qualiry hatchling growth pellet staple and supplement with small insects, worms, and chopped fish. Keep those pics coming, they should grow pretty quickly in the first year.
It was just a regular milk crate standing on its side so it didn't take up tank space. There were some threads in here awhile back about DIY turtle docks/basking platforms that I was thinking of trying, right now my turtles are in a big rubbermaid until they get a bigger tank.
