Awesome m8 answer so sorry for for the confusion please forgive lol, Newbies for you i suppose Sorry and thanx for the info as it was really helpful. Especially where plants are drinking more water than nutrients as of dehydration is it?.
Yeah, that happens when the humidity drops below a certain point (Don't know what that point is exactly). But it's a combination of low RH and High Temps over 80. The higher the temp, the more the plants lose through transpiration, so the more the drink for the roots.
Question. Are you leaving the tent open throughout the photo-period? That will help a lot. Also, if your ballast has a dimmer, turn it down to 400, even 250 for that little space will work wonders. I just saw that your temps are OVER 90?! Yeah, leave it open until you can get your heat problem worked out. That will kill the plants, not to mention the little seedlings in there.