Hey! Those turtles are very attractive kids!
For wounds: definitely keep the water as clean as you can. It doesn't look like the tank is all that big, so doing 100% water changes once/week shouldn't be a problem for the next few weeks until the sores heal. Also, feed them both in a separate pan of water if you can. That will also help keep the water more clean since there won't be any leftover food-bits to cloudy the water (pellets are especially bad when it comes to clouding the water).
If there are white pockets on the shells, that might be a sign of shedding. Have any thin layers of shell come off yet?
I have to agree with what everyone already said about the cramped quarters. There are people on this board who have been able to separate turtles by using rubbermaid containers (so they don't have to buy a huge tank....cheaper this way). I have seen turtles fight over territory before & it isn't pretty. Do something about it now before one of them loses a tail or something.


