Newbie! Enclosure & food questions

[ileolai]

Hi guys!

I just got my first Northern BTS about two weeks ago. He's about five-six months old and seems to be settling in well. His name is Magnus.

I'm totally new to keeping reptiles, and I'm just looking for feedback on the set up I built, in case I can improve it.

So what I have is a 36 x 18 x 18 inch modified wooden rabbit hutch, because I had an unused one lying around. I took out the bars and replaced it with mesh, waterproofed it, etc everything to make it as close to a commercial vivarium as possible. [I realize it's a bit small and will be upgrading the size when he grows. The mesh is also temporary and will be replaced with glass doors soon.]
He has a 100 watt infrared basking light and 5.0 UVB provided by a two foot, T8 strip light, about 18 in from the substrate, 12 in from the basking area [worried this is too high to be effective...]. The temperature gradient goes from 38c to 25c [100f-77f].
His lights come on around 7am and go off at 8pm, I leave the basking light on a bit longer. He likes to bask late in the evening.
I use this mini hemp stuff and oat hay for substrate. Humidity is around 50-60%. I read Northerns can go as low as 30-40% so I hope this isn't too high.

What do you guys think?

Also, just a quick question about diet -- I'm feeding him K9 Natural dog food for the most part, because the meat/veg ratio sounds good. It has calcium and vitamin D added already -- should I still supplement, given that?
He gets fresh veg, fresh meat, hand raised snails and superworms as well.

Thanks for your help! :] Here's a pic of my lil dude.