Don't know what I'm doing wrong can somebody fill me in

On more so in the middle to bottom leaves in seeing what kind of looks like burnt tips. I did start my plants in a nutrient rich soil so my thoughts is maybe nutrient burn but not sure. They seem to be growing kind of slow as well. It's northern lights strain if that matters any. My humidity stays between 32 and 36 and my temp is usually about 80. Any thoughts would be greatly appreciated. I'm almost positive I don't over water. So maybe underwatering? Idk.

Looks ok to me, just a bit of nute burn. they should bounce back soon and take off. Your rh is kinda low tho cheers!

Thanks