I lowered the UVB.A large aquarium or plastic tub would be easier to heat and keep humid. Also, I only see one light fixture. Growing baby tortoises need UVB either from the sun or from an expensive UVB light.
Sorry - on second look I see a tube type fluorescent fixture. That's probably your UVB, right? It seems a bit high, though.
Did this do the trick for you and the family tortoise?I lowered the UVB.