Seedling starting to droop, help please!

First time grow so still learning a lot..

My seedling has started to droop recently. DWC setup, water is a few inches below net pot (only added water to the containers recently as the root has just started to come from the bottom of the net pot. With the airstones on, the bottom of pots are getting wet. I believe that the drooping was happening before water was added to the containers.

Water has nutes at 25% of recommended amount on bottles, EC 0.4, PH 5.8, water temp around 19c. Tent with lights on humidity in 40s and temp around 26/27c, lights off around 21c. Humidity is a bit low and am trying to work on that.

I want to try and fix this before it gets any worse, could this be due to the low humidity or is it a case of under/overwatering.

Cheers,

Looks thirsty to me-or on the flip side too much water

Raise water level a bit can also cut a pop bottle put it over the plant to raise humidity just pop some vent holes in it.

Thanks fellas, will raise water a bit and keep an eye on them.