So I wake up this morning and check my temps like I usually do. I keep my 2 vivs on a metal rack, with adjustable shelves. My top viv was fine 94 on the warm. But my bottom tank was at 86 on the warm. Now I'm thinking its getting colder in NY and that was the cause for the drop, but the temps were fine at night when I went to bed. Anyone have this happen to them and know how to remedy it? I turned up the thermostat and the temps started to climb so my UTH is working. My UTH is smaller on my bottom tank than on the top tank, could this be the problem? It doesn't make sense to me because if the overall room temp dropped shouldn't my top tank also have had a drop in temp? And I know tubs would fix this problem but I usually don't have problems maintaining steady temps in them and I need a couple of months before I buy my rack, so any suggestions besides get a tub would help.

Thanks for the Help