Amnesia here I Come

12 inches is too close for your light at this stage of growth, you see the serations curling up...thats a sign of light stress. Too much light can cause all kinds problems. I looked at your nutrients and im seeing only .23tsp per gallon of calmag.....i'd go 1tsp per gallon. Feed ph looks good, however also check your runoff ph to make sure its not out of whack at the root zone. I'd put the lights at 24 inches and within a few days you will see a difference. Happy growing.

I'm sure peeps will agree that's a Calcium deficiency.Get some Cal-Mag.Is that Coco your growing in,and are you using Coco nutrients.If your using normal nutes that's your problem and you may need Calcium all the way through your grow.You should always try and confirm it somewhere else though.Iv seen some dodgy advice on here.

so sad. I feel for you. when they look very healthy and then start doing things like that. :( sorry, I read something recently about when it starts and looks like that on the side but I can't remember what it was. and since it doesn't just start on the side for you but also in the middle, that would probably be a false statement as well. or maybe two different problems. good luck. someone here will definitely give you a solution as a response.

Love the "Wooooow" in the background at the perfect timing😂😂 wow indeed! And yeah as mentioned below drooping leaves alone are a clear sign of water damage, the moisture in the air stopped the moisture in the soil from evaporating thus resulting in a soaked soil for long periods of time which harm the plants' root system! Roots also needs Oxygen to grow and the soil aerates when it dries. Try increasing the air circulation in the tent to reduce humidity or if possible bring a dehumidifier for a more precise climate control! Hope this helps! Good luck and happy growing :)

Long exposure to humidity levels that high could definitely knock her around a bit. The soil looks damp, she could be suffocating if the water is not moving away from her roots, lack of oxygen. If you start seeing fungus gnats, that's a good indicator that there is water retention.

Yeah, and due to high humidity the water in the soil doesnt have time to evaporate so the wet dry cycle is probably fkd as well, meaning probably overwatering too. Good luck and stay lit growmie.

Light burn happens at the very top and moves down. Yours is middle top so would have to guess it's nuits.