I just built a melamine rack for my ball pythons (7 tubs high) and I installed 11" flexwatt up the back panel on the inside of course, currently my herpstat is set at 115 degrees and I cannot get the inside of the tub over 79-80 degrees, is there always this big of difference in temp vs setpoint? And is it safe to raise the temp on the flexwatt any higher? Any advice is much appreciated!