A little Help for a LittleGreenman! (any help appreciated)

I am a fairly experienced grower but this is my first grow with auto's using the ebb/flow type setup.

The top set (newest growth) of leaves is drooping and I can NOT figure out why. I did a res change yesterday and got no changes. It really looks like moisture stress of some sort but I really can't figure out why, I've tried watering less (once a day), I've tried watering more (once every two hours), I've tried not watering, nothing, no changes.... I'll post some pics so you guys can see.

It really looks like overwatering (and with the addition of the HPS thats the first thing that popped into my head) but they actually get worse when I water them and get no better when I refrain from watering

I need help NOW please. anyone with experience please assist.


These are the conditions as of now.

Light: 600w hps about 20'' from the closest plant (20/4, autoflowering plants)
Temp: 77
RH: 40-75%
Medium: Hydroton (recentlly leeched of salts)
Floods: 15 minutes, ph of 5.7-6.0
Watering: once every 5 hours for 15 minutes
Res temp: 60F
Res water: 550ppm (200ppm cal/mag, 150sensigrow, 150, sensibloom, 50 from superthrive/ph down)

Attached are a few pics.

1. One of the plants under a CMH (lookin happy), the larger plants still drooped a lil in this setup during the end of the day but nothing like this before I rearanged and threw in the HPS

2. One of the plants after I moved them, but before this strange drooping appeared

3. two days later, all plants drooping, no idea why

It's possible you have root rot. Even though res temps are on the low side (where they should be), there are still some pathogens that are able to replicate, causing damage at lower temps. If this is the case, look into a Silica product like Pro Silicate.

Let me know if this helps. Keep us posted!

Couple of thoughts...

If it's only Hydroton and you let it go dry, root damage may have occurred...

Photo 5 looks more like it's drooping from heat off the light and lack of water...

Might try watering one from the top ( using water out of your res. ) every 4 hours and see how it reacts...

Might want to back off the 600w till your figure out the problem...

Food for Thought...