drooping and yellowing

I am useing coco with general hydroponics,I've been having issues,with several plants,most look like this,and some worse,had some look fine one day and next completely leaning over,some died,any ideas?

Looks like overwatering

Yea, id say overwatering or underwatering. Whats your water/feed schedule like?

If they droop from one day to another and then just die then its ph for sure.. make sure you check your ph aftwr mixing and let it sit for a few hrs then check ph again wright before watering.
You can tank me later b.

I'm useing g.h been having issues thow u don't think it's nitrogen,I've been thinkin bout trying Lucas formula any thoughts on that?

This pick from today,I'm useing g.h,do u think it's nitrogen? Been thunk in bout the Lucas formula,any thoughts

The plant looks fine today. I run coco and perlite 80/20 and these are key. PH 5.7-5.9. Nothing else! Cal Mag at 4ml/gal EVERYTIME you water/feed. I use (CaliMagic). Young seedlings/cuttings get fed at a TDS of around 400, Veg 700, Flower 1000. (I feed everytime) You know you have it right when your leaves are a beautiful green with no burnt tips or curling. The TDS at my faucet is 75 and I have very clean water so I use tap. Most coco people use R/O water. Most also suggest a 10% runoff when watering. I don't follow that all the time. I do flush heavily the last week - week and a half (every 2-3 days) until my runoff is around 100-150. The only problem I have anymore is if my PH meter isn't calibrated correctly and then a lockout will happen. 5.7-5.9 is a small range and a .2 difference if your meter is off can make a difference. Best of luck.

Add some mycorrhizae, molasses, and silicone powder to your watering regimen and your plants will thank you. Fulvic acid and humic acid is good too. I don't use GH so don't know what the flora line has in it.

It definitely looks like over watering.