Ok, you're doing good and what a beautiful tortoise! For a brunette he has some beautiful markings. Both of mine are wild caught and the brunette male i have has scars all over fom shell rot.
Ok, anyway, don't keep it in a glass enclosure, you want something they cannot see through. All the visual stuff freaks them out and they become HIGHLY stressed. Make sure you have UVB on them during the day. I use a UVB and heat bulb from Zoo Med. Works well and they always bask in the light.
Carolina pet supply has as suppliment called TNT which is great for grassland tortoises. It can be full of probiotics or be lacking probiotics, up to you. It also adds ALOT of calcuim to their diet. If you feed them spinach you need to add calcium in LARGE quantities. I have read that spinach in RT's does the same thing as Bearded Dragons and binds the calcium not allowing them to digest and use it properly. I could be wrong but i have had no issues, so far.
www.russiantortoisepictures.com/forum/index.php is a great resorce for any questions, suppliments, or advice but it's nowhere near as good as ball-pythons.net
I tried alot of things with my guys: cuttlebone, calcium powder, commercial tortoise mix, etc. They only like the stuff i buy at the store. I get an organic veggi mix. Some Iceburg is okay, but not in large quantities. It has no nutritional value to it literally starves them. Remember, variety is important because they like to try new things. My guys will pick at everything and ignore anything with powder, anything commercial, or anything out of the ordinary especially cuttlebone. They are good torts, though.
Food for RT's is not the same as food for box turtles or any other type or land turtle or tortoise. Why? Because their nutritional needs are different. Bod turtles, red foots, really mopst types of tortoises need some sort of protien and they usually get it from their caretakers giving them pinkies. This is bad for RT's and can causemassive problems. RT's are herbivors and digest certain things and need alot of fiber. Other types or tortoise don't need as much fiber and are mostly concerned about protien. I have has a cherry head and Russians so i'm not sure about ALL other species or tortoise or land turtle.