Hi, I keep horsfields and I am in the uk. I have quite a large group ranging from 25 plus years old right down to week old hatchlings! Your tortoise looks about the same size as one I have that has 2013 captive bred, although they al, vary in rate of growth even from the same clutch. You have had lots of good advice about lights and heat so I thought I would throw in an extra idea or two.I have my adults outside but my younger ones inside in an indoor Guinea pig cage. The younger ones don't like glass all around , they like to hide and they also like to climb. I would suggest making his enclosure a little more interesting. Hills, tunnels, pebbles to climb, different textures and sight breaks. Above all lots of places to hide. Also they can take a long time to get used to a new home and boy, Russians are stubborn! Get the temps right, break up that large expanse of glass and I reckon he will be stomping about in no time. I have attached a picture of my indoor cage. Please excuse the current lack of plants in it, what they didn't eat they trashed
