I have had a pretty cold basement and a super low humidity most of this winter. My gold leaf plant was constantly showing signs of nitrogen toxicity even though I kept nutrients and PH in check. @niala worked with me and we determined the issue was too much air flow. Too much air flow reduced my humidity regardless of my humidifier and kept my tent cooler forcing me to run the heater on high - this meaning I have a major source of heat both above and below the plants. I’m sure that hurt the humidity too.
Most people say you should replace the air every 3 minutes. Well in a typical 4x4 tent is 112 cubic feet. So you only need fans that move 38 cfm. Most of us have 230-440cfm fans.
My solution was to use a timer instead of a potentiometer. I have my fans run for one minute, then shut off for two minutes. By doing this I have my heater at half the power and don’t have to run a humidifier in my tent. I’ve also gotten temps manageable between 60F and 82F.