Question About Tanks Vs. Rack System Setup

i wish i could keep my living room at a steady 75 or so, wife loves to play with the thermostat constantly, drives me crazy

i have my heat tape set at 95(which is about 92 on the surface of the newspaper, and my cool side is 85-83. i have my room temp in the low 70's, but my heat tape gives off enough heat to heat the cool side.