So i've read a bit about people who have their bp's in a tub only having one or no hides. I'm moving my 1100g-ish girl into a 40qt (from a 20gal) and was wondering, If I only have one hide, should it be on the hot or cold side?

Setup will be: no rack 40qt tub, 2 pieces of 11" flexwatt, dimmers + thermostat = homemade proportional thermostat, cloth and foam boarding to semi surround the tub.

If I put 2 hides in, she'll have almost no room to move around. So, hot or cold side?