Hydrofarms seem to be a ok unit I have been testing one (really testing it) and have as of yet been able to force it to fail. It as noted is not an accurate unit it cannot be trusted to read temps correctly. The three I have been paid to test read high. What is says the temp is, is wrong. I would not suggest to trust it that way. It also has a longer 'throw' than I'd like myself it seems to be about 5º in total hi to low. That is quite a long way. Glass tanks however don't give up heat quickly and in a fairly warm room will likely work well tubs on the other hand heat very quickly and cool very quickly, so I'd suggest hydrofarms with a single tub set up (direct heat) in a cool room (less than 77ºF) to be a poor choice. Before anyone jumps on me for that make sure you have read my post carefully. I am tired of explaining direct heat and indirect heat warm and cool rooms are not the same.
Okay so, just to make sure I understand correctly...I get that the thermostat I mentioned is not the most accurate but do you mean that it's OK to use on a TANK and NOT a TUB or OK to use on a TUB and not a Glass TANK?