extreme claw, post flush, new growth

[inreplyavalon]

Heya folks.

As the title suggested i noticed the runoff of my coco was about 2000ppm and i was only feeding 1000. I was seeing some lockouts and discolorations. It was caused from watering without any runoff, most likely.
Now it is three days after the flush and the new growth on most plants is doing a serious CLAW. Looks like they got hit with wat too much nitrogen, but they did not.

In general some of the plants look better already from the flush, but some have this claw going on. Do you folks think this will let up a bit over the next few days?

I flushed with about 1/4 strength nutes. 300 ppm. until runoff was about 350-400.
Thanks folks

 

[LJB]

The claw is typical of overfeeding, but if you're sure that is not the case, than something else is reducing the plant's ability to uptake water.

What is the temp. around the plants and the humidity?

Are you using only coco?

Flushing works perfect against a excess of N (NO3-) or P. But if the problem is excess Ca, then flushing won't solve the problem. It will usually help a bit and may also aggravate other problems induced by excess Ca. K, although still being uptaken as cation, is easily flushed too. But Mg and Ca don't respond well to flushing. Both get bonded to over 90% of total coco colloids in normal conditions, so keeping an equilibrium between the two is the key when growing in coco.

This also explains why runoff pH and EC readings are incomplete.

 

[inreplyavalon]

LJB thanks for the kahnowledge.
Overall they are looking a lot better post flush. It took a few days but 90% of them look a whole lot better. Greening up and starting to bud a bit.
I also hit them all with Bushmaster at the start of bloom(for height issues), and that usually can really exacerbate over fert issues.

It also seemed to help when i pumped on my CO2 generator to 1500ppm last night. Today they look like they sorted through some issues. Maybe the increased CO2 gave them the strength to process some salts. Sounds good to me...

 

[hazy]

You said you flushed with 1/4 strength nutes. When you finished the flush did you hit it with normal strength nutes?

The claw is said to be a N overload around here, but I'll bet you a dollar that that's is wrong wrong wrong. It's far more likely to be a Calcium def. Caused by you flushing all the Ca out of the medium maybe since you say it had not started before you flushed...

My experience with clawing caused by overnuting and therefore lowering pH till Ca and Mg lock out, is that flushing will cause new growth to be flattened out. If you finish the flush with nutes so you don't get even more defs.

 

[inreplyavalon]

Thanks for chiming in Hazy.

I did increase the nutes to 1/2 strength for a day after the flush and then full strength the day after that. They looked good for a day or two and then today they are clearly showing some signs of nit. overdose. I think the reason for it is that when i flushed and for a few days after i raised the lights quite a bit. So i am hoping that the lights were to high to process the amount of N i was feeding. So i lowered them and will see tomorrow. Today a common theme was that the plants on the edges were the ones that had the dark green and new growth claw.

All this aside, i am on board with your diagnosis for my original problem. New knowledge for me and it is appreciated.

 

[inreplyavalon]

well i chaecked my runoff ppm for the group runoff bucket and it was at 1500ppm. I am shocked. I flushed them down to 350ppm about a week ago and have been feeding Heads 6/9 formula with 120ppm tap. It comes out to about 1050ppm. I am surprised they have buildup in such a short amount of time. Well we'll see what happens next...