Something to look out for is the res temps. Its not so much the temperature that is ran, but the change in water temps. I have noticed that when I top off, it lowers the res temp by like 8 degrees. From 72 down to like 68f. I also noticed when lights go out in the winter, the res temps drop from 72f down to like 66f. If your running 15 degrees cooler at nights, its going to be very hard to keep a stable res temp. Chillers work great and so do heaters, air pumps also work great. Im just saying, if I had my way, every tote would have a heater and a chiller, set to 72f, but its economically dumb to do that. Once you start pumping electricity into your system, well coco drip seems so much more affordable. Im not saying the drastic change in res temps is causing alot of my issues, but I have yet to rule it out. With no air pump, no heater and no chiller, the water in the tote will get very very warm, then when lights off, the temp drops. I know you say you like the drop in temps for the plant, and ill agree, yet as for the roots, i dunno, I really want to say thats the cause of most of my issues. Anywho, just food for thought, better give ya the info than not give it to ya.