In winter my cham lights are on from 8-10 hours a day, in summer 12.
I've used 8.0 with no issues on adults, but for babies its better to use a 5.0 that's a couple months old. So you might want to let your 8.0 burn for a week (constant) at least before using it on your new baby cham and make sure there's lots of folliage so it can get out of the UV if it wants
and I agree about watching temps - little ones do dehydrate fast