Drooping plants :(

[AlphaPrime]

Hi all - sorry for the short post am at work on my phone...
4 X Kosher Kush roughly 4 weeks post germination.

My setup is as follows:
-Secret Jardin 100x100x200cm tent
-Aeros IV: 4 Bucket DWC System

1x 20L Master Tank and Fittings
4x 20L Tank, Lid and 120mm Mesh Pot
4x Haelia 100mm Air Stone
2x Marina Air Pump and Air Line

-4 inch Carbon Filter
-6 inch Systemair RVK A1 extraction fan
-4 inch Systemair RVK --> used as intake
-Powerplant Aircooled reflector
-600W Lumatek Digi Ballast
-600W HPS Bulb
-Hailea 100 water chiller set at 66 deg.

Woke up today to find my babies looking rather sorry

I don't know what could be wrong - did a full reservoir clean and change 2 days ago and they were fine right after.. Even grew a bit during the time - then this morning my plants looked like this.

See grow journal for setup details and previous pics.

Ph this morning was at 5.7, rh was good and water temp spot on ! Ppm at 850ish.

Water level was also perfect and plenty of air coming from air stones.

This is what they looked like just yesterday

Please help !!!!
First Solo Grow - DWC Kosher Kush

 

[AlphaPrime]

Would something like Advanced Nutrients Revive do more harm than good ? Am desperate and dont want to lose my first set of plants

 

[cyclo1224]

i cant say anything about the specs of your set up...but i can tell you those plants look healthy to me. whats the temp in the room?