Personally i think when dealing with ppm or Feeding there is a lot more then just having optimum lighting . for each 10 degree rise the plants metabolic rate doubles this means more nutrients and water is needed not at a high percentage if a person is growing in a cooler room with optimum lighting being that its colder the plant will not use as much nutrients ..
Hammering your plants or force feeding , with higher EC / PPM your just throwing your money away plants do not need lots just a good well balanced diet and they will Rock...
Years ago i used grow in the 74- 76 Degree area , since bumping up my temps to 88 degrees my growth rates doubled ...
Maybe Captain will bump up temps to 85 - 86 lower nutrient levels and up the water and see if he notices a difference.. this is where i think we All can see better THC levels plant growth and better GPW .. there is no Denying them plants grown near the Equator just destroy there Northern sisters .. in yields and THC and its pretty hot temps