Leaves curling downward

Hello can anyone tell me if this is overwatering or heat stress or under watering , or light stress, top of plat is a foot below the bottom of my cool tube

Get your conditions right. Only water when the top 1" is dry. I think the biggest mistake I made when beginning was overwatering.

That plant is stressed from something... looks like overwatering... but could be multiple things.

Put your hand, palm down, at the height of the plant, under the cooltube. Does it feel uncomfortable? If so, it's too hot for your plant, move it up. Make sure you have drain holes in that pot. Add a fan to help dry the soil faster. Only use plain RO for a while...