I had a previous post on the temp in my viv, and how hot the Flexwatt was under the tank. It still seemed so hot that I got smart and un-stuck the thermometer from the side and laid it on top of the aspen and found the temp was 100*!!! When it was stuck on the side of the tank BELOW SUBSTRATE LEVEL it was showing a max of 86*? Now I'm really freaked. How do you all check the temp at substrate level because the ambient temp registered sure isn't correct. Can you use like an indoor/outdoor thermometer that has a wire probe and lay it on the warm side substrate or something like that? As always, you guys...gals too are the best.