Help please . Pretty please.

[Willtech]

Hi Guys ,
My biggest Think Different isn't a happy camper. These spots have started appearing . I didn't think too much of it at first as it was only a couple of leaves out of hundreds but it's definitely spreading across the top of the canopy albeit slowly. What do?
Being fed half rations of sensi bloom A+B
Density cal mag
Carboload
Bud ignitor
Nirvana.

Under 600w Hps and a 100 w LED. That's for all 3 plants not just this one .

The new growth looks fine it's just the older leaves that seem to have it but I'm really concerned as this girl is massive and I'd hate for it to go tits up at this point.
Thanks in advance for any and all help.
Go easy
W.

 

[Renaissance Redneck]

@Willtech, my eyes aren't so good right now, but that looks like phosphorus def to me. Maybe the beginning of K def as well? It's also hard to see everything under those lights. Can you get a shot under natural light?
How is she handling the 1/2 rate of bloom nutes? Assuming your pH is good, upping the P and K would be advisable.

 

[Willtech]

@Renaissance Redneck .
Thanks for your reply .
Given that I have 3 plants here but one is probably 3 times the size of the other 2 would you recommend that the big one gets its own feed regime ? They are all just now getting the same feed mix from the same 5 gallon drum of spring water . Should I be looking to beef up the nutes for the big girl ? I know you can't tell me exactly what to do and I wouldn't expect you to but my thinking is a plant that size is gonna require a bit more than the other 2 . The "normal" sized ones are on cruise control and seem very happy so I don't want to change anything there. The big one looks like it's going to need a lot of attention in the next while.

 

[Willtech]

Ok.. this is the one and only time it's leaving the tent as it's quite hard to manoeuvre.
Hopefully you can see on the pic what's happening.
Thanks in advance
W.

 

[Renaissance Redneck]

@Renaissance Redneck .
Thanks for your reply .
Given that I have 3 plants here but one is probably 3 times the size of the other 2 would you recommend that the big one gets its own feed regime ? They are all just now getting the same feed mix from the same 5 gallon drum of spring water . Should I be looking to beef up the nutes for the big girl ? I know you can't tell me exactly what to do and I wouldn't expect you to but my thinking is a plant that size is gonna require a bit more than the other 2 . The "normal" sized ones are on cruise control and seem very happy so I don't want to change anything there. The big one looks like it's going to need a lot of attention in the next while.

Again, it's tough to see everything under those grow lights, but I would definitely up your P and K.
Sensi B has 1.5% N, and most of that is the slower release urea. If you aren't seeing any signs of too much nitrogen (burning tips, clawing, etc), I'd keep the part A rate the same and move up to 3/4 strength on the part B. That's where your higher P and K values are . Just for your problem child. If the other gals are happy, stay in the zone!
A great resource for identifying issues :
https://www.autoflower.org/threads/...panded-to-include-other-issues-as-well.43164/

 

[Willtech]

@Renaissance Redneck
thanks for link . I'll give it a good read just now .
I understand how hard it is to diagnose when not actually in front of the plant so your help is very appreciated. It makes sense that a big one like this would need that extra boost with nutes . I've been playing it kind of safe with them as I had a bit of nitrogen toxicity a few weeks ago so I thought this problem might be toxicity rather than deficiency. I'll up the part B sensi and see how it goes.
Go easy,
W.

 

[Renaissance Redneck]

@Renaissance Redneck
thanks for link . I'll give it a good read just now .
I understand how hard it is to diagnose when not actually in front of the plant so your help is very appreciated. It makes sense that a big one like this would need that extra boost with nutes . I've been playing it kind of safe with them as I had a bit of nitrogen toxicity a few weeks ago so I thought this problem might be toxicity rather than deficiency. I'll up the part B sensi and see how it goes.
Go easy,
W.

If you're sure it was N tox, I'd go 1/4 strength on the A, and 3/4 strength on the B.

 

[Willtech]

@Renaissance Redneck
Yeah very sure .. super dark green leaves and the "claw". Backed off with the base nutes and it was sorted with if a few days .

 

[Rev. Green Genes]

Don't forget to let us know if it fixes the problem. My guess was going to be an old problem of N tox, where the new growth is fine, old necrotic areas wilt. RR is right though, those necrotic spots and dead tips are exactly what happens in hydro when the pH spikes out of whack and won't allow p or k absorption. That big one needs it's own mix or you will end up with toxicity in the smaller ones I would think.

 

[wiltstone]

I get that sometimes but only under my cmh315 if I dont have the room under a hps I give it a good water with calmag, silica and even a little more mag then next water I bump up my pk but thats without the claw. You might want to move it to the part of the tent that gets the least LED light and adjust your nutes renaissance redneck prolly has a better handle on that I'm not really familiar with your nutes.

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