I am starting a new build using the IM Nuvo 20 AIO. I already have a IM 100INT, and this is my first experience with an AIO. The first question I have regards the water level in the return section. How much lower than section 2 should I keep it? Or is it alright to keep it even with section 2? Also, which compartment is preferable for the heater? I was thinking the return section, but I'm not sure. Thanks for any guidance!