New Rainbow tank advice

Hello all!

Just purchased a gorgeous rainbow boa rehomed from Craigslist. She was in a tank way too small in my opinion, and she's a little skinnier than I'd like her to be, but in terms of BRB she's frickin' gorgeous, a good eater, and way more curious and docile than I've typically seen. She has the temperament of a chill ball python (granted, she tagged me.)

We have her in a 30-40 (I think it's 40, but it might be 30 idk) gallon open top tank. It's kind of under construction, I'm hoping to rebuild the top with half tempered glass or plexi-glass to help trap humidity. Have a medium UTH but I have it on the side of the tank not the bottom, I didn't want her actually making direct contact with it, as well as a 100 watt ceramic heating light both on one side. Put a few hide spots, 3 larger water dishes (she can fully fit in them all) and some grape vines over a hefty bed of coconut fiber. I have a side thermometer in the cold side reads 49 - 64 (depending on the temp of our house), and a point and click one I check the warmer side with, seems to be around 74 - 76 typically. I pour water in daily so the fiber is always dark brown and I must her daily too until I can re-build the top to trap it better.

Any suggestions, or recommendations, would be super helpful. She's definitely different than the ball pythons, or the red-tailed boa we own / owned. Guy thought she was about 2 years old, she's about 2 ft long.

Side note - I've owned and handled snakes for 8 years and NEVER got bitten, I've always been very aware of their body language. The (un-named) BRB wrapped herself up in my ponytail. After a while, I reached up to feel where I could grab her to pull her down, thinking her head was down by my neck. Sure enough - I was wrong and she tagged me pretty good. I think I have to name her after a vampire now....

I keep and have bred BRB's. They need high humidity to survive, never mind thrive.

Instead of wasting money trying to make a fish tank with a CHE do what it physically can't (maintain 75% humidity at all times), get a tub with a securely locking lid like this:
http://www.lowes.com/pd_579877-62860...d=50150118&Ntt=

Move the under-tank heater from the tank to the tub (they don't go in the tub, always underneath it), and get a thermostat for the heater.

Cool side temp should be around 75*F, never under 70*F. Warm side should be 85-86*F, you can run the UTH up to 88*F (note that's UTH temp not ambient air temp).

If/when your snake ever outgrows that tub - and it will take years - you can get a proper PVC reptile enclosure for it.

Also BRB's are called "slender boas" for a reason. If you're used to handling ball pythons then they may seem too thin when they're really a correct weight.

Great advice above. Humidity is crucial especially with one as young as yours seems to be. My tub with my BRB always has a ton of condensation on the front. I would guess its above 90% humidity.
I seriously doubt your boa is two years old if it is only 2 feet long. Mine is over 2 feet and is not even a year old. Unless of course they underfed her?