The CLAW!

[bufo marinus]

The Claw! Anyone who has played around with hydro will probably run into this problem, but what the hell is it? and why do you see it linked with so many different problems to grows with seemingly no problems?

 

If you think about a common cause for a case of the Claw eg high temps, what happens? Temperature at the root zone rises to a level that causes conductivity and ph to soar at the root zone to dangerous and sometimes fatal levels. That is it in a nut shell.

The ways that problem can be produced is many and varied, as are the end results.

Root bound? sure, fresh nute solution can't wash away root exudes OR provide fresh oxygen around the root zone, conductivity rises, the Claw starts

Shitty air stone in the rez, not enough oxygen at the root zone, conductivity rises, the Claw

Times between flood and drain too far apart, root zone temp rises, conductivity rises,..

Not calibrating your truncheons, insufficient watering times, res solution too low and temps rise marginally during middle of the day,... the list goes on, but the end result is still the same.

This gives credence to why big pots are a good idea, why we should change/measure nutes correctly, why a big res constantly topped off is a good idea etc etc but really comes back to the number one item of importance and that is too keep the root zone at an optimum state

[bufo marinus]

I know I was peelin' pretty hard this morning after half a dozen cones, but just wanted to raise this subject I've seen a few pics here lately that have leaf curl problems/the claw, call it what you will, and thought it would be a good discussion topic for hydro.

I'd say most people who are seeing this happen at this time of year would be due to the high temps lately

Anyone want to comment? Anyone not agree/agree or think my line of thought is off?

[bufo marinus]

Hmmm no replies, everyone must be up with this one then? All thats needed now are a few examples, here's a nice one from stoney

 

https://cannabis.community.forums.ozstoners..._205_124024.jpg

 

another one from Gazza2001au

 

https://cannabis.community.forums.ozstoners...st&id=19383

 

and a room full from chato

 

https://cannabis.community.forums.ozstoners..._284_126415.jpg

 

happy gardening

[nugget]

Aren't those three examples all caused from the use of PGR's? I know Stoney Chato & Gazza all use Rock Juice or something similar and this is known to cause leaves to droop in this way too

 

I may be totally wrong though.

 

 

[bufo marinus]

Well I'm glad someone replied

Let me say first up this thread is about nothing more than a discussion on nutrient uptake problems and not a barbed attack on anyone or their style of grow.

I can only answer your question with another question nugget, do you think those plants looked 100% healthy?

Here's another one to mull over

Chato mentioned he added Superbud at half strength and blamed that for his problem... how could adding a nute supplement at half strength produce an over fert condition??... the plot thickens

[thc24]

dont know the cause of the claw have not seen it in my garden with or with out PGRs.

 

if followed by leaf damage id think ec was alittle high or if on an indica with big fresh leaves and passes within a week = normal, leaves often take a few days to form or grow normally..

Edited December 16, 2006 by thc24

[bufo marinus]

Thanks for joining in thc24. You've not seen the claw? You must run a very tidy ship. I like to think I keep things in order too, but I have seen the claw and when it has reared it's head in the past it has frustrated me to the point of giving up hydro altogether.... almost

Now you also said in your post that leaves take time to form and grow normally. I don't follow? The entire plant, indeed ALL the plants in Chatos room had a mild case of the claw so??

But you also commented that the EC was too high. I would agree. But! why would adding something at half strength produce an over ferted condition? This is what I'm getting at.

To cut a long story short, what could cause the electrical conductivity to rise to a toxic level in Chatos DWC system after adding a nute supplement at half strength?

As for the other two pics from Stoney and Gazza, did you notice the similar leaf damage? It reads like a blip in the plants life cycles, both in early flower stage.... only the owners can provide more insight on those but I would be guessing that the heat wave we had in November had something to do with all 3 grows actually.

Here's another one to mull over now that I've mentioned heat, why is an inert substrate like coco so effective?...

 

Edit substrate

Edited December 16, 2006 by bufo marinus

[thc24]

what i ment by forming leaves was the newest leaves on tips of branches often look alittle mutant, hash plant has very stubby fat leaves if plant is growing fast the new growth can be curled or slightly clawed thats normal by the next day or two theres a new set comming through and mutants are now normal looking leaves.

 

 

claw or large curl on fan leaves i cant explain my leaves go either pale, burnt or bug damaged sometimes strange spots on lower leaves when coco hasnt had enough flushing. alittle tip burn on last 3mm of fingers on fan leaves is common in my grows but doesnt get worse or claw if stop increasing the nute.

 

 

water temps this time of the year could be the cause i know my res temps are above 23c .

most of the day hotter when res is getting low.

 

Coco is very good at insulating roots from hot or cold one of the reasons i swapped from rockwool cubes, also has good water/air ratio when not saturated. i just find it an easy medium to use with half of the problems i had in rock wool, always healthy roots with rhizotonic in the coco.

 

 

 

 

plants drink alot more water this time of the year, in a recirc grow ec would increases faster than it would have during winter, but i wouldnt think it could get to toxic levels within a week.

 

 

 

 

Bufo never give in ,

 

i got frustrated with my old setup could have stuck with it but swapped over to coco and growing has been alot easier more consistant and am able to scrog with pots, in rock wool i just let them do there own thing often with different sized plants at harvest.

[bufo marinus]

Ok thc24, I understand what your saying about the new growth, this is not what I'm talking about.

You say your water temp is above 23C and that could be the cause as this time of year temps are a problem, I would agree with that.

You said that coco was a very good insulator from heat and cold at the root zone BANG! Spot on!

You also said

plants drink alot more water this time of the year, in a recirc grow ec would increases faster than it would have during winter, but i wouldnt think it could get to toxic levels within a week.

Toxic level? where? in the res? or at the root zone?

Unless we're reading whats coming back into the res, we can't read what state the root zone is at

I have let a plant in a pot of coco dry out, to the point that it droops, given it a water, read the EC of the run off and watched it go off scale on a truncheon! BUT! the EC back in the res only went up by 0.2.

Saying all that, do you think it was the addition of half strength Superbud on it's own that caused Chatos problems OR the addition of Superbud to a system already high on the EC scale, that for reasons clearest to the grower saw a rise in EC/PH at the root zone to a dangerous level?

 

Bufo never give in

 

I appreciate the sentiment my friend, but that was a long time ago

I will just say the first system I had saw a case of the claw so bad I had to throw all my mothers and start from scratch.

[bufo marinus]

Ok, just to show nobodies perfect, I have a shot of some of my own plants with The Claw!

Things were going fine with this crop till I got a bit side tracked with other things, of the female variety...

Just as the plants were starting to flower I neglected to water for a day or so and the pots really dried out, some more than others, but at the same time temps went through the roof, causing I would say, the EC & PH to rise and hey presto, The Claw.

 

 

Now this lot were salvagable but still did not reach full potential, some were close some were average,

Here are some pics of the finished bud. Exactly the same strain of cuttings, same pots, same shared nutes. The only difference was that some were thirstier than others at the time of EC rise

 

This plant had minimal damage and still frosted up nicely, notice the vibrant calyx

 

Where as this one you can see the calyx are curled back into the bud and trichome production is not as good.

 

Edit; Bummer, the pics turned out as thumbs

Edited December 25, 2006 by bufo marinus