Urgent help needed (pics inside)

Hi

As the title says i need some help.
I'm growing in coco under an HID 600w, using dutch pro nutes A&B.
Temps and air flow are good.

I've ran into a brick wall and don't have a clue what could be wrong with my plants, i've recently had some temp problems but
i've got that sorted for over two weeks now.
A few of my plants look like they're dying, to me it looks like nute burn. The problem is, is that i only fed them at 1/4 strength and
wouldn't of thought that would do this damage.



By the way, i have been just feeding them just water for the last week in-case there are any salt build up and i'm going to start a rotation
of FEED,WATER,FEED,WATER.
Not all of my plants are showing this damage but around 25% of them are.

Any ideas?

ok, so...are you in veg or flower right now?

what's your runoff PH?

....I did this once using CalMag that was nitrate based... they went downhill really quick too...

I'm in veg at the min, about three weeks in from cuttings.
I haven't checked the run off yet, but they are due a water tomorrow so will do it then.

I've been pretty spot on with my ph levels on the way into the pot always at 5.8, but as i said in my original post i've had some problems with heat.
So i fed them just on water for a week in-case the water was evaporating to quick and leaving the nutes in the coco (salt build up).

bump.

Any opinions welcome.

Someone will answer. Hang in there for a touch. How bad was your heat? Do you test with a ph meter or strips? Do you know the ppm of your nutrients?

When the leaves curl like that it usually means Nute burn...couple that with heat issues,
bad news...lower your dosage, see if they pull through..if not scrap the fucked ones.

I tested the Ph of the run-off it came back at 5.79ph on the meter, i left the run-off in a bowl over night and tested it again in the morning and it read 6.5ph so it raised 0.8ph.

The clones have been on just water for over a week now and they are showing signs of nute def (Yellowing of leaf edges). I fed them on a quarter strength dosage of nutes then when they were thirsty gave them just water, which leads up to yesterday when i gave them a half strength dosage.
So i'm feeding,watering,feeding,watering etc I'm gonna stick to half strength and see if they spit their dummy out again.

I'm hoping they will pull through but they don't seem to be showing many signs of recovery, just playing the waiting game now with fingers crossed.
At-least it's not all of the plants effected and can salvage something from this massive F-up.

in hydro when in doubt flush, till there starved and feed on!

are the 25% effected all in the same area if so then look at groom issues, all should be affected the same if they are clones, is your source reliable?

did you reuse your coco or prep it before the plants went in??


your coco looks dry!!! you should need to water every day under a 600 hid!

try day 1 ph water, day 2 ph nutes day 3 leave to dry out. see if this helps!!

p.s if ph is going up the plants are doing what they should be if it goes down, panick! lol

hope this helps!!