a whole bunch of questions

I have a whole bunch of questions!!!! I cleaned out the turtle’s tank today (at -10, it’s a little too cold here for her to be outside) and noticed that on her bottom side, her shell seemed to be peeling and a little soggy. I don’t know if all DBTs act like this but here are some of her characteristics. 1-she does NOT bask. We have the UV light in there a nice big space for her to bask and she spends all of her time in her little “carport” shelter. I took the lid off her shelter with hopes that she might dry out, and she stayed in the water all day instead of basking anywhere. In the summer, when she’s outside, she spends most of her time out of the water and in her shelter. IS she weird or am I doing something wrong (or both)? What are your thoughts on sulfa blocks–do you use them much? 2-she does not eat commerical foods and won’t touch food other than goldfish (except in the summer when she will nibble strawberries and apples, etc). Can anyone recommend some aquatic plants that might be safe for her tank that she won’t tangle in? She gets reptisol in her water and a cuttlebone (that she will not touch). I’d like her to get more calcium and variety in general. I am going to buy some crushed coral for substrate. BTW, she is FAT! 3-we have very hard water and the turtle has some calcium scum on her shell. Is there a good way to clean it, I tried to gently rub her back with a sponge, but she still had a ring of buildup. BIL told me to try Armorall, but that seemed a little weird. If I put betadine on her, is that safe to have her get in the water and swim in it later? WHat can you wash a turtle shell with? I know turtles don’t get washed in natural settings. 4-What are good things to clean a tank with? It’s not filthy, but since we have hard water, the calcium also clouded up the side of the tank. I scoured it with a little vinegar and rinsed it well. We clean it regularly and change filters regularly. I read the stuff on several pages about turtle care, including Chun’s page (thanks Chun) but am just wondering, is it normal for the bottom of her shell to be peeling? How often do females shed scutes? When can I expect her to try to lay eggs? Sorry about the questions, but I think all of you probably know more about this than I do! Rowena