Heat was not a problem with this set up. The fog was cool. I never did check the ph of the nutrients after it came out of the fogger and collected on the bottom. I just wasn't sure about the demineralization cartridge and what that did to the fog produced. I didn't like having to watch it all the time. The reservoir held two gallons of water and did not have an automatic shut off function. Since the instructions warned not to add anything to the water I just envisioned it failing sooner than later. I also did not like the instructions for cleaning the darn thing.