Are these Zn or S def symptoms?

[elcoloan]

@Waira , this morning I found some leaves on the tops that have some blotches... some are light-brown-yellowinsh, others are lighter. Any thoughts?

 

[Waira]

What's your light sched' mate? I'm wondering if that could be a contributing factor,... 24/0 is very dubious for actual benefits, if you're running that!
these new symptoms are hard to call, but way up top smacks of a micronute defc., maybe B.... you may be getting on top of others, but it's very possible micro's are still behind the curve so to speak,.... This is a concern I've had with MC before, and have asked GLN about it,...
Nothing major there so far, so let's see if it halts, micronute defc.'s can be a bitch to fix, especially if you don't have the right supplement to deal with it,...

 

[elcoloan]

What's your light sched' mate? I'm wondering if that could be a contributing factor,... 24/0 is very dubious for actual benefits, if you're running that!
these new symptoms are hard to call, but way up top smacks of a micronute defc., maybe B.... you may be getting on top of others, but it's very possible micro's are still behind the curve so to speak,.... This is a concern I've had with MC before, and have asked GLN about it,...
Nothing major there so far, so let's see if it halts, micronute defc.'s can be a bitch to fix, especially if you don't have the right supplement to deal with it,...

The light is 12 inches from the tallest top. It's dimmed to 60 Watts (from 120 max)... manufacturer actually recommended it be closer. I do 24/0 because of temperature, I'd go 20/4 if I could, but lights off and it immediately goes down to 18 C / 64.4 F during the warmer yet rare nights. With photos I don't usually mind the low temps, but with this auto (my first) i really wanted to pamper it as much as I could and provide it with better temps at least.

 

[elcoloan]

.... spots and blotches in upper part of the plant didn't halt... they got worse and lower section kept losing leaves. Some blotches are orange-reddish, others light green, other light-brown.

Maybe P or K def symptoms or some micro up top, Mg bellow? or could the upper symptoms be because of the 24/0 schedule? I don't think it because of lights too close, since blotches are appearing even in leaves not directly under the light.

I notice the blotches show on main colas and on the leaves of the upper and upper mid-sections of the tops that are becoming nice buds. Resin production has started also... so I assume it's a deficiency from all this new flowering production. Plant has several purple stems, even the stalks have purple lines. That's why I'm thinking P def, but maybe K is missing too. Also think I will do a watering with OG Biowar Roots pack in case they are symptoms of root root.. thing is I would expect root rot symptoms to show in the bottom as well and these are just in the top mid section.

I'm almost positive the lower section symptoms is due to a Mg def. I reduced Epsoms by half last reservoir refill to compensate the increase of the PK sup and not burn the plant... obviously not a good idea.

My plan for now is to increase Epsom back to previous level (to help with the Mg def), and increase the dose of Bud Explosion a bit more (for possible P or/and K). I could also increase the dosage of MegaCrop (version1), but last time I increased it I got burnt tips everywhere in the plant, so that's why I'd rather increase the other two. What do you think @Waira ?

The past week she had been getting 673 ppm / 1.346 EC (tap 77, cal-mag 44, 419 MegaCrop 1, 82 Epsom, Bud Explosion 51). Last monday she began with a new reservoir at 690 ppm (tap 89, cal-mag 47, 425 MC1 , 46 Epsom, BE 84 ). Always set pH to 5.8 and on next reservoir change it's usually at 6.1-6.2 .

Here are some pics taken today from the symptoms in the upper section.

 

[Waira]

.... lights are OK for intensity and distance... I get the dilemma with T and lights. I use a small space heater in my tent when it's running because it's in an outside courtyard. Keeping the lowest T over 65F+ is a big help to the plant's uptake and metabolism...

So, after more than a week of elevated ppm's and she's actually getting worse, with multiple defc. symptoms still, I can only conclude something is screwed with the damn coco... Best bet is some sort of antagonistic uptake issue, and/or pH in-pot, not the soln. going in,... This is the down side to bottom feed pots in coco = ... We are blind to these two very important factors, pH and ppm load in-pot,... More remotely in likelihood is a root problem, not to say both can't be in play... The snag with MC is you can't elevate parts of the feeds to deal with things like micronutes defc. (and this is still looking like B defc to me) without adding in more of what you don't want.
....purple petioles isn't a good diagnostic clue because many strains have this as normal expression, but purple striping on the stem is a clue to overall nute defc., which we suspected early on here,...
Lowers I can't see, but likely it's N, maybe Mg defc.... N is normal up to a point as you know, but if it's Mg, it's not because of lack at this point! Again, back to antagonistic uptake issues,..
Only thing I can think to do mate is to pull the pot off the res', and do a coco-style flush... more feeds haven't helped, and my best guess at this point is a cumulative imbalanced salt build-up in this pot... I can't be sure if the coco's CEC buffering with Ca/Mg is off either, but it's suspect...
...flush soln. recommendation I saw was with RO/Di water + 150ppm Ca-Mg, + 150ppm nutes, pH 6.0; pour through until inputs are at or near run-off values...
With your 77ppm water (nice!) you can use that, go 200ppm total tap + Ca-Mg, but keep nutes at 150 initially... The idea here is to test that initial flush r-o for ppm and pH to see if we are on the right track with this, purge excess if that's the case, and see if the Ca CEC buffering and be "rebooted",... give her a day, then hand feed at the usual ppm's to restore what's been stripped out of there ASAP, and same for the res'....
You can speed up further draining by placing the pot on top of some newspaper and a paper towel or two that has direct contact with the drain holes to facilitate capillary action.... This pull more air into the coco too!
This is frustrating, I know, I'm pissed too...

 

[elcoloan]

.... lights are OK for intensity and distance... I get the dilemma with T and lights. I use a small space heater in my tent when it's running because it's in an outside courtyard. Keeping the lowest T over 65F+ is a big help to the plant's uptake and metabolism...

So, after more than a week of elevated ppm's and she's actually getting worse, with multiple defc. symptoms still, I can only conclude something is screwed with the damn coco... Best bet is some sort of antagonistic uptake issue, and/or pH in-pot, not the soln. going in,... This is the down side to bottom feed pots in coco = ... We are blind to these two very important factors, pH and ppm load in-pot,... More remotely in likelihood is a root problem, not to say both can't be in play... The snag with MC is you can't elevate parts of the feeds to deal with things like micronutes defc. (and this is still looking like B defc to me) without adding in more of what you don't want.
....purple petioles isn't a good diagnostic clue because many strains have this as normal expression, but purple striping on the stem is a clue to overall nute defc., which we suspected early on here,...
Lowers I can't see, but likely it's N, maybe Mg defc.... N is normal up to a point as you know, but if it's Mg, it's not because of lack at this point! Again, back to antagonistic uptake issues,..
Only thing I can think to do mate is to pull the pot off the res', and do a coco-style flush... more feeds haven't helped, and my best guess at this point is a cumulative imbalanced salt build-up in this pot... I can't be sure if the coco's CEC buffering with Ca/Mg is off either, but it's suspect...
...flush soln. recommendation I saw was with RO/Di water + 150ppm Ca-Mg, + 150ppm nutes, pH 6.0; pour through until inputs are at or near run-off values...
With your 77ppm water (nice!) you can use that, go 200ppm total tap + Ca-Mg, but keep nutes at 150 initially... The idea here is to test that initial flush r-o for ppm and pH to see if we are on the right track with this, purge excess if that's the case, and see if the Ca CEC buffering and be "rebooted",... give her a day, then hand feed at the usual ppm's to restore what's been stripped out of there ASAP, and same for the res'....
You can speed up further draining by placing the pot on top of some newspaper and a paper towel or two that has direct contact with the drain holes to facilitate capillary action.... This pull more air into the coco too!
This is frustrating, I know, I'm pissed too...

Darn... I think I have confirmed today that it has all been a mix of root problems (stinky stinky rot!) and surely my underfeeding during stretch. I had already had some root rot symptoms early on so it's not unexpected, and i've heavily underestimated this plant's nute needs.

After posting here I took out the pot out of the tray, let it drain and then instead of just filling the tray with the bennies, I watered 2 Lt of bennies from the top and let it drain into a pan from an elevated position. It started stinking up the room as soon as the first drop appeared from below... I recognized this awful smell immediately from clones i've let rot, and the color of the runoff was green.
After this sorta flush, I let it drain for an hour and then put it back into the tray and let the tray fill from the reservoir with nutes as they were before but added more Epsom and bud explosion. When I came back to the forums i saw your post saying to give here a day before feeding again at normal strength... . Will empty the tray and let it refill tomorrow. Thanks for the help!

I might be crazy, but I feel she liked the bennies a lot. Think I might do another flush in seven days.

BTW, I know it's not the same as the pH inside the pot, but I do daily checks of pH and EC of the water in the trays and the reservoir... and several times per day... just for curiosity sake. I check 3 times per refill... i check the tray when it's full (a few minutes after it refills from the reservoir), then when it's half full, then when it's almost empty. With this plant, EC of the tray has never been above the EC of the reservoir, always 10-50 ppms lower, and pH is always 0.1-0.2 higher than the pH of the reservoir. I make fresh reservoir mixes with pH at 5.8, and when I go to change it it has usually risen up to 6.1-6.2, so tray pH has been at max 6.4.

Here she is today before the bennie treatment

 

[elcoloan]

Colors got worse. But aromas exuding from the plant have improved so much. Smells like sweet mangoes.

 

[Waira]

foooock,... dammit! Bloody rot, I was afraid of that,....
.....this is looking like S defc. kicking in as well,.. (I see more necrotic patches too (P defc.), not surprising, S is an immobile nutrient, and it's in high demand now just like P... yup, inoculants should be a regular thing, they will help the plant with nutes/uptake indirectly but importantly....
Good on the pH, that's a bit low but not bad,.. Note that S can get locked out below 6.0...
Also good on the aroma, she's clearly tapping deeply into the fans for what she can get that mobile within the plant... Epsoms are a help being MgSO4...
The bottleneck is the roots mate, little work-around here now that you're in bloom,.. foliars are risky! But it could be done if you applied it carefully, with the right soln. mix, wetting agent and precise spraying... a mild low/no scent castile soap will do in a pinch. This makes the solution coat and stick, not just bead up; spraying the underside is most important, there are more stomata there and that's the only way into the leaf unless you happen to have optic Foliar Transport ( a carrier that can temporarily allow penetration through the leave's cuticle layer, dragging nutes along with it)...
Pistils do not like this, the tips may brown out, but that's aesthetic worries, not functional ones!
solution needs to be weak, MC and epsoms total about 300ppm-ish, pH to mid 6's....

 

[elcoloan]

foooock,... dammit! Bloody rot, I was afraid of that,....
.....this is looking like S defc. kicking in as well,.. (I see more necrotic patches too (P defc.), not surprising, S is an immobile nutrient, and it's in high demand now just like P... yup, inoculants should be a regular thing, they will help the plant with nutes/uptake indirectly but importantly....
Good on the pH, that's a bit low but not bad,.. Note that S can get locked out below 6.0...
Also good on the aroma, she's clearly tapping deeply into the fans for what she can get that mobile within the plant... Epsoms are a help being MgSO4...
The bottleneck is the roots mate, little work-around here now that you're in bloom,.. foliars are risky! But it could be done if you applied it carefully, with the right soln. mix, wetting agent and precise spraying... a mild low/no scent castile soap will do in a pinch. This makes the solution coat and stick, not just bead up; spraying the underside is most important, there are more stomata there and that's the only way into the leaf unless you happen to have optic Foliar Transport ( a carrier that can temporarily allow penetration through the leave's cuticle layer, dragging nutes along with it)...
Pistils do not like this, the tips may brown out, but that's aesthetic worries, not functional ones!
solution needs to be weak, MC and epsoms total about 300ppm-ish, pH to mid 6's....

The rot I'm 99% sure is from freaking fungus gnats I haven't been able to control and I wasn't keeping in mind as I should've. Got some spinach in Kratky buckets and their roots are always white... i check roots regularly and a few days after I find a gnat stuck in the roots they start turning dark, smelly and weird burnt/deficiency symptoms occur up top, and the plants die. Also, the coco coir I've been using comes with lots of gnat larvae, so it's difficult to avoid. Can't find any BTi (other BT yes, but not the israelensis), and Amazon won't ship it to my country.

Back to the plant... seeing her bad looks on Monday, yesterday I decided to do the low EC flush you recommended @Waira, but instead of CaMg I used Epsom in the flushing solution. After flushing I waited several hours and gave some microbes. Still waiting a bit to resume normal feeding. New feeding I plan to keep at 1.2-1.3 EC.

Any how, details of the two flushes yesterday:

-Flush #1: 9am... took the reservoir solution which was at around 1.4 EC (containing mc, epsom, budexplosion, camg) and diluted it in tap water (67 ppm) until it was at 367 ppm / 0.734 EC, and set pH to 6.0. The resulting were 5 Lt of this solution which i watered slowly form above.... initial runoff was 707... final was 680.

-Flush #2: 10 am... prepared 5 Lt at 443 ppm / 0.886 EC (67 ppm tap, 215 MCv1, 161 Epsom), 6.0 pH. Took these 5 Lt and watered first with only 2 Lt... runoff was 507... then watered with the remaining 3 Lt and runoff was 430-450 ppm. Run off no longer smelled bad.

-Bennies: 9 pm... after more than 9 hours after final flush, I gave 500 ml of microbes (OG Biowar Root pack). Didn't measure EC og bennies solution, but a little runoff came out and it was at 500 ppm /1.0 EC.


Today I feel she has more green to her leaves.... Plant to resume normal feeding later today. I never do foliar applications, so I don't have a mister. Will look around my home to see if a find something for that. Thanks for the help!

 

[elcoloan]

Feel she's doing better.

After daily low EC, 6.0 pH flushes last week and some beneficial microbes, she’s been having her watering last two days with 590 ppm / 1.18 (68 tap + 342 MC1 + 87 Epsom + 93 Bud Explosion). New reservoir tank to be activated later today has nuts al ready prepared at 610 PPM / 1.22 EC (69 tap +383 MC1 + 92 Epsom + 66 BE).

Pics from today.