I've kept pythons in the past, but this is my first boa. I've wanted one for ages and finally took the plunge during the Tampa reptile show last weekend. I just wanted to make sure I have a proper set up for her as I know they're more particular than ball pythons.

She is an '09 hatchling who just took her third meal last monday (and fourth today!) so she's quite small, maybe 16" or so, and petite. I picked up a tank from glasscages.com at the show which is 24"x12"x4" or so and with a glass top to keep the humidity in. I have a heat pad on a dimmer switch keeping the substrate about 84-86F at the top and around 90F if you check the glass, using an infrared temp gun. Ambient temp inside the tank is approx 78F and humidity seems to stay between 77%-84% depending on whether I had the lid off for a while or not (the room itself is about 54% humidity).

Now, I have two questions! The first is regarding substrate as I have her on shredded aspen, but also have a bag of cypress mulch in the house. The humidity is pretty stable around 80% with the aspen, but when I tried cypress the accurite registered only "HI" which I can only assume is 100% relative humidity. I don't want to "overdo" the humidity and make everything soggy so I was wondering if I'm fine with the aspen since it stays upper 70s-low 80s.

Second question is regarding my heat pad and the temperature I set it to. I know they can't handle temps of 90F+ for long and the ideal is 85F with ambient of 75-80F, but if she decided to burrow she might contact the 90F down by the glass. Can I assume she wouldn't be stupid enough to do that if the surface temp is ideal, or should I set it for maybe 87F tops on the glass and live with a lower surface temp like 81-83F?

Thanks in advance! Given that she ate today, I don't think my husbandry is too terrible, but I'm a perfectionist and I'd like to provide the best possible conditions for her.