I'm planning an indoor enclosure for a 1- or 2-year old Russian that I'll probably be getting, but I'm not sure what to do about UVB lighting. I can let the tort roam around my back patio for half an hour or so most days, but there is foliage from neighboring trees blocking the sun, so any sunlight that reaches the patio will be filtered. Will the tort be able to receive enough UVB from the indirect and dampened sunlight, or should I set up a UVB fixture in the enclosure as well?