Is this a burn or a deficiency worth addressing?

[terp182]

If it's mostly coco, I would treat it like coco as much as possible. I grow organic now, but when I was using nutes and growing in coco, the highest ppm I would use would be 550 max.., and that was in late flower.. I also wasn't feeding (using nutes) with every watering. It's much easier to add more or something if needed, than it is to remove excess if too much of something is added. I would definitely check the ppms of the rum off and try be in the 200 range.. You don't necessarily have to "flush" the medium. You can just use plain water for a few days then recheck the ppms. But either way, 540 is super high for week 2. These are the ppm ranges I use for autos

W1- 100 ppms
2- 200
3- 400
4- 450
5- 500
6- 525
7- 525
8- 525
9- 550
10-550
11-400
12-0

This varies and all depends on what the plant is showing/saying. These are just general ranges to help you avoid nute burn and lock outs.

Finally went in and flushed with 200 ppm for 3 gallons (couldn't get to it for a few days and it was all I had on hand that was dechlorinated) and it was indeed 1000 ppm runoff, with a pH of 6. I got it down to under 500, and we're hoping she turns around with a couple more waterings without nutes. Thanks again for the insight!

 

[terp182]

Those last changes got her into shape and she sprang to life, however she's in trouble again. I can't tell if it's too many nutes (highly unlikely) or not enough. The autopot is on and giving her ~470 ppm MC, calmag, SC and a little kelp.

Can anyone help me get this girl back on track? The Double Grape next to her is taking off (the CDLC is not perfect but in much better condition) and on her lower leaves she just doesn't look happy. New growth looks pretty good, which is why I came here.

Any insight is appreciated as always!!

 

[elcoloan]

i know I nag a lot about pH lately but it might be your issue... did you ever do the slurry test? What about your reservoir pH?
As a reference, if you can't do a slurry... my reservoir's pH is usually 0.1-0.2 below what my tray is at after the tray is about half empty. Might not be the best pH indicator but i think is better than nothing... and I like to also check EC of the tray... when iive had buildup or root issues, both pH and EC of trays vary greatly to the reservoir's.

 

[terp182]

Thank you! I hadn’t done the slurry test because I don’t have distilled water but am picking some up tomorrow. The res pH is 6.1 and it’s individual reservoir pH was 6.2. The other healthier plants’ res pHs were 6.1. Got the 6.2 quickly down to 5.9 with some diluted ph down in its own res. Should I ph down the main res to 6.0? Or lower? Thanks again man. I also gave a light epsom foliage feed just in case it would help. Appreciate the advice! Slurry test tomorrow.

 

[elcoloan]

Thank you! I hadn’t done the slurry test because I don’t have distilled water but am picking some up tomorrow. The res pH is 6.1 and it’s individual reservoir pH was 6.2. The other healthier plants’ res pHs were 6.1. Got the 6.2 quickly down to 5.9 with some diluted ph down in its own res. Should I ph down the main res to 6.0? Or lower? Thanks again man. I also gave a light epsom foliage feed just in case it would help. Appreciate the advice! Slurry test tomorrow.

I would advice the pH of the res be set according to what you get in the slurry (high pH over 6.5, set reservoir low like 5.8ish... low pH below 5.6 , set reservoir a higher than 6.0 around 6.2-6.4). Asumming your medium is in a correct pH range, your tray and reservoir pH numbers seem right, though... so do try to set you res a bit lower and see what happens... as long as it's between 5.8 and 6.3 it should be fine... and if you notice the plants in lower pH seem better, that might be your answer.
But what's the EC in the trays after they are halfway empty? Whats the EC in the reservoir? Is 470 ppm you final ppms after adding all (MC+SC+CaMg+Kelp)? If so, the plant might just be underfed. But I feel you're using too many things and you might have a lockout because of this. Also, how high are your lights? I would get them a little further while your plant recovers and just use MC... I'm amazed at how so many people can get MC to work well with so many things added.. everytime I add something to MC i start getting problems.

 

[terp182]

Man this girl is really stumping me. I went in and revalidated main and individual res pH. Main was at 6.0, while the indiv res for this one was 6.2. Slurry test from soil an inch down was 6.5. So I flushed with just under a gallon of MC-only water at 490 ppm/5.9 ph. Runoff was 490 and 6.0. So all good, I thought.
A day later, the necrosis or whatever brown and dying spots are increasing and still moving up nodes. I’m not sure what to do at this point - I can’t find any bad data points to adjust, and the other two plants on the same res are thriving. I’d love to at least learn what I did wrong (I still strongly suspect lockout somehow), but this girl might just be done for.
Really appreciate the guidance, elcoloan.

I would advice the pH of the res be set according to what you get in the slurry (high pH over 6.5, set reservoir low like 5.8ish... low pH below 5.6 , set reservoir a higher than 6.0 around 6.2-6.4). Asumming your medium is in a correct pH range, your tray and reservoir pH numbers seem right, though... so do try to set you res a bit lower and see what happens... as long as it's between 5.8 and 6.3 it should be fine... and if you notice the plants in lower pH seem better, that might be your answer.
But what's the EC in the trays after they are halfway empty? Whats the EC in the reservoir? Is 470 ppm you final ppms after adding all (MC+SC+CaMg+Kelp)? If so, the plant might just be underfed. But I feel you're using too many things and you might have a lockout because of this. Also, how high are your lights? I would get them a little further while your plant recovers and just use MC... I'm amazed at how so many people can get MC to work well with so many things added.. everytime I add something to MC i start getting problems.

 

[elcoloan]

Man this girl is really stumping me. I went in and revalidated main and individual res pH. Main was at 6.0, while the indiv res for this one was 6.2. Slurry test from soil an inch down was 6.5. So I flushed with just under a gallon of MC-only water at 490 ppm/5.9 ph. Runoff was 490 and 6.0. So all good, I thought.
A day later, the necrosis or whatever brown and dying spots are increasing and still moving up nodes. I’m not sure what to do at this point - I can’t find any bad data points to adjust, and the other two plants on the same res are thriving. I’d love to at least learn what I did wrong (I still strongly suspect lockout somehow), but this girl might just be done for.
Really appreciate the guidance, elcoloan.

Hmmm... i'll have to tag in @Mañ'O'Green or @Waira for this one. For now while they chime in, i'd say just keep the MC at EC of 0.8-0.9 / 400-450 ppm and 6.0-6.2 as you have and a bit of calmag (30-50) ppms and se how she reacts).
Asuming your environmental numebrs are in check (RH and temp) the other thing i could try and think of that could be causing this is root problems (bugs or root root or something of the sorts... maybe some bad nematode). Got any benneficial microbes at hand (eg., hydroguard)?

 

[Mañ'O'Green]

I think you have a problem in that Roots Organics mixed with coco and perlite is not soil or soilless! When you flush that you get the easily dissolved salts but the organic amendments remain behind. This makes it very difficult to get back into balance.

Stop chasing the symptoms now because that is unreliable with so many changes. Top fertigate PH 6.2 with 50% strength balanced nutrients plus 50 PPM Calcium - skip the magnesium if you can. Fertigate to 30% run off and remove from the reservoir. 2 hours before lights out top water PH 6.2 to 30% run-off remove to waste. The next day go back to your normal autopot schedule with 50% strength nutrients. Do not be too concerned with the looks of the plant. I have had some very burnt-up looking plants still produce well.

 

[terp182]

No hydro guard but the roots I can see look ok, but I can easily pick some up regardless. I’m going to keep her in those specs and see how she does, and eliminate additives to the MC except for a bit of calmag. Temp and RH are both good - 78/79 and waning from 60 down to 50% RH, currently at 56%. I’ve been watching VPD pretty carefully. Thanks again!

 

[terp182]

Thanks for this! Completely agree that I made a bad audible call in adding soil - I should have just stuck with coco/perlite.

When you said 50% nutrients, about what ppm would that be? I think my last fertigation/“flush” could qualify as the first one of that, though at a slightly lower ph. I can do a second flush at your specs (not sure where to get a cal supplement but I can find one I’m sure) and let her go.

I really appreciate the help, as does my Sativa loving girlfriend who’s tolerating this grow because of this sick girl.

I think you have a problem in that Roots Organics mixed with coco and perlite is not soil or soilless! When you flush that you get the easily dissolved salts but the organic amendments remain behind. This makes it very difficult to get back into balance.

Stop chasing the symptoms now because that is unreliable with so many changes. Top fertigate PH 6.2 with 50% strength balanced nutrients plus 50 PPM Calcium - skip the magnesium if you can. Fertigate to 30% run off and remove from the reservoir. 2 hours before lights out top water PH 6.2 to 30% run-off remove to waste. The next day go back to your normal autopot schedule with 50% strength nutrients. Do not be too concerned with the looks of the plant. I have had some very burnt-up looking plants still produce well.