As I said in my other post regarding your purchase.. you may wish to reconsider on getting 2 turtles. A 10 gallon tank is barely adequate for one turtle let alone two. If you can't afford upgrading and the necessities, you really are better off with just one happy turtle instead of 2 that aren't quite as happy. For 2 hatchlings, you should start with a 20 gallon tank. As I said, if you can't afford a good setup from the start.. seriously think of just getting one.
Just so you know, I'm not trying to be arrogant or nasty.. but I've been there done that and this is experience speaking. Fortunately I had the funds to provide all that they needed up to a point. I started out with 3 turtles, one for each grand child.. and gave one to my daughter because I knew that I'd not be able to have multiple huge tanks if for any reason they didn't get along or if one got sick.
Something else you may wish to consider if you do decide to get 2 turtles is to use large rubbermaid containers, they will suffice while they are young and are much less expensive than upgrading to larger tanks as they grow. Just something to think about
