I bet your ph has gotten to low used all your nitro in the beginning stAges. I’m using 2 1200 Philzon leds in a 4x4 and keep it at 13 from the tallest part of the canopy and make sure my higher parts are towards the outside of the light concentration. Personally I think your plants used a the stored nitro like it Would before cut. If you got 2 months left of flower I’d slowly increase a bit of nitrogen or if you know thats not the case. Your ph is prob just to low for a long period used all the nitro. I found out my ph pen was f*cked when I’d calibrate it and ph water to 6.5 found out it was really around 5.2 All Green leached out during veg f*ucked the run. And opposite outside fed outside plants all summer in the garden with the hose natural ph of my drilled well is 7.8 fucking plants grew like a sumbitch cause of the high ph letting all the nitro build up and then when they flowered there wasn’t enough p or k or something I’m not a nutrient pro. Good luck bro I tried to follow and see what week your in but my brain got tired following posts.