x2 on the http://www.reptilebasics.com/hide-boxes
I would replace your hydrometer/thermometer combo you have. Do you have a UTH? If so, is it connected to a thermostat?
I like these to measure the ambient temp and humidity (amazon link), but if you do have a UTH, it won't measure the surface temp where the UTH is placed, I would then get an Acu-Rite from Walmart. You can also measure with a IR gun, but IR gun's are not he best reading temperatures on shinny/reflective surfaces like glass. If you don't have a thermostat, but do have a UTH, you need to get a thermostat, I also included a couple links for those.
Thermometers/Hydrometer
http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1
http://www.walmart.com/ip/Acu-Rite-I...00000027727770
Thermostats - I like the ones from Spyder Robotics, if you are unable to get one of these, pick up a Hydrofarm.
http://www.amazon.com/Hydrofarm-MTPR...ords=hydrofarm
http://spyderrobotics.com/