What's going wrong? Looks like Ph...

[Benbenny]

Hi all,

 

I'd been having some problems with my babies that resolved after reducing nutrients. However, now I have some other issues coming up. The leaves and branches are dying off from the bottom up, and it looks like it's a Ph problem. See photos. They have been growing about 6 weeks, just turned back, ec is at 1.1/1.2, ph 5.9-6.1 (and I check it daily and readjust it if needed). I dipped the pen in the coco and the top reads around 6.3, but the ph of the run-off was reading 6.8/7.0. I've flushed twice in the past week with Ph adjusted water and it makes no difference to the Ph of the run-off, still reading 7.0 after six flushes today alone with water adjusted to Ph of 3.5 (desperately trying to bring it down!). I don't get it. All the salts come out, but the Ph remains high and it's killing my girls. From the top they look fine, just this is creeping up from the bottom.

 

Any ideas?

[Reverend]

A little more information please.

What size pots, how much did you flush, have you got drainage in the bottom of the pots.

[Foreskinnius]

check for little tiny bugs under the leafs

[everest]

yep , looks like been ate by spider mite

 

ev

[Benbenny]

50 litre pots, flushed six times in one day with about 450 l of water adjusted to 3.3ph. I've checked under the leaves and in the coco, no evidence of bugs.

 

If there is some kind of bug, why does the Ph of the run-off stay at 7.0? This is where the problem is...

[loylty gets u nothing]

u in a white tent?

any chance of whole plant pic?

[loylty gets u nothing]

are u using any addatives?

wat brand coco?

was it flushed prior to planting out?

is the coco pre buffered?

wat brand ph meter?

maybe get soem drops to compare readings

can u calibrate the meters?

all the best

bil

[Chato]

You have something toxic in your grow-room would be my best guess.

 

Cheap pots or hose or something that's leaching, could even be possibly via air from heat on plastic or paint but that would prolly make your ph swing like crazy rather than stick solid at 7 so i;d guess pots first.

 

Do you have any clones or seedlings or other plants showing signs?

 

Good luck.

 

peace

c

[GIY]

given the provided information its really hard to say.

 

Yes pH is really important for optimal growth but plants will happily grow without clinical symptoms in pH ranging from 7.5 to 4 so don't get too carried away with the pH its not your problem.

 

Coco can tend to get a little wet and if your flushing as much as u say i am gunna guess that this may be the problem.

In addition the pH fluctations could also be explained in terms of poor aeration/ water logging as anaerobic conditions will make pH do the funny things u see and make the plants look like they do. Also you need to rule out pests so hit the medium and foliage with pyrethrum, do not use any synthetic versions only use pyrethrum (very good reasons why)

 

My suggested course of action:

>WATER ONCE WITH DESIRED NUTRIENT LEVEL

> NOW LET THEM DRY OUT BEFORE WATERING AGAIN

> Up the temp to 30 if possible

> Put a fan across the surface of the pots

> aerate your pots with a spike without damaging roots as much as possible

 

Now the fastest way to treat the plants for quick recovery is with foliar nutrients. Use what we call a shot gun mix get a complete foliar fert.

 

Also i work as an agronomist and complete tissue tests will cost you about $50 so you could grind the leaf up (so its unreconisable) and send it to your local elders, landmark, airr, or CRT store and they will send it to a lab for you, this will give you a certain answer if it is nutritional.

[Chato]

Actually after reading your previous threads and issues with PH maybe a good starting point would be to change batteries in your ph pen and make sure it;s calibrated correctly. Also ph up and down don;t last for ever so possibly replace them as well if they are a bit dated.

 

peace

c