Calcium def?

In a couple days my NL in hempys are on their 4th week since flip.
Today I noticed these brown spots on some of the leaves towards the top. Only one plant affected. Think its a bit paler than the other as well.
Haven't changed nutrient ratio or anything in a couple of weeks, except switching from using my water tank filled with tap water instead of straight from the tap. Feeding them every 48 hours but considering going daily cause they do droop a little sometimes after 48.



Room is 3.3'x4.4'. Extraction fan at 30% 24/7 and 100% if it reach a certain temp. Two oscillating fans on 24/7, one over canopy one below/partly hitting one plant directly.

3x 240w QB 3500k UV+IR
17.5" - 19.5" from top growth.

Temp: 65f - 85f
RH: 35% - 55%

5 gal Coco/perlite 30/70 hempy
Ata max a+b 75%
Calmag 25%
Hydroguard 100%
PH 5.8

It also have some other older leaf symptoms but as far as I can tell they are not progressing and only happen where its tightly packed, lacking light or a bit windy. Clawing, tacoing and yellowing.


It's the one on the right that got the spots. Threw in couple bud shots.



So what u guys think?

Should I up the calmag dose?

I think you should up the cal mg to 50% and back off the N, I see some clawing and finger cupping. If your base has high K, like 1-2-4,That can affect cal absorption too. At your next res change you might try adding the cal mg at 50% of recommend strength, wait a day or two and then add your nutes at like half of what you have been giving them. Up it if you see any defs but I bet they have enough food absorbed to go a few days to a week. The few dead leaves In your picture are nothing to worry about. You have a nice full canopy it won’t miss a few lower or shaded leaves.

93OG said:

I think you should up the cal mg to 50% and back off the N, I see some clawing and finger cupping. If your base has high K, like 1-2-4,That can affect cal absorption too. At your next res change you might try adding the cal mg at 50% of recommend strength, wait a day or two and then add your nutes at like half of what you have been giving them. Up it if you see any defs but I bet they have enough food absorbed to go a few days to a week. The few dead leaves In your picture are nothing to worry about. You have a nice full canopy it won’t miss a few lower or shaded leaves.

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I'm currently on bloom nutes which I believe is low on N. My calmag contain some N. Finger cupping and claw have been there since veg nutes(3 weeks ago since I switched to bloom).

I'm on board upping calmag dose makes sense cause I'm in coco. A little hesitant on lowering bloom if the only reasoning is N related clawing and fingercupping?

With this new info u still think I should lower bloom?

I think you should lower it. I’m going by what your plants need right now. I would say if they have been clawed and cupped for 3 weeks it’s even more of a reason to give em a little break. Try it for a day and if they drink a gang of water they’re looking for more food. If they drink an average or a little more they are doing good. Your leaves are pretty dark and a bit shiny, cassis N symptoms. If I’m wrong you might loose a gram of final weight. If in right you might gain an oz. just my opinion though.

93OG said:

I think you should lower it. I’m going by what your plants need right now. I would say if they have been clawed and cupped for 3 weeks it’s even more of a reason to give em a little break. Try it for a day and if they drink a gang of water they’re looking for more food. If they drink an average or a little more they are doing good. Your leaves are pretty dark and a bit shiny, cassis N symptoms. If I’m wrong you might loose a gram of final weight. If in right you might gain an oz. just my opinion though.

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I'll lower a+b by 25% and up calmag 25%. Considering they are drinking it dry in two days I guess they drink OK.
NL is a bit dark and shiny as I understand it. But I hear u.

So cupping and clawing would fix itself if corrected, unlike yellowing leaves? If not, the time they've had the symptoms doesn't weight in.

In my experience the leaves usually flatting out in a few days or a week.

93OG said:

In my experience the leaves usually flatting out in a few days or a week.

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That's great. Then I can check if this helped or not. Gave them 50% a+b and 50% calmag.

It seems like it's mostly at top canopy. Might it be light burn?

Still progressing on one of my ladies. I lowered the nutes two days a ago and this time they really didn't hang on for 48 hours. When I entered the room 8 hours ago she were hanging down, unable to support the branches cause of thirst. Gotta make some sort of support. Used rope and tape for now.

But does this mean I should give more nutes again? The other plant were fine and as far as I can tell she is bigger and should go dry sooner. U can tell by overall colour which is which.

Am I getting this right, you cut your regular nutes back by 50% and upped your cal mag to 50% of the recommended amount, like 40 hours later the plants were droopy?

Did they drink the system dry or drooping with water available?

93OG said:

Did they drink the system dry or drooping with water available?

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Yeah there werent any water left. Drank it all.

I backed down on regular and bumped calmag up yes.

Previously I used 75% regular 25% calmag.
Last time I fed them 50% regular 50% calmag.
All % are of max recommended dose.

PS. Only the plant with spots drank herself dry, even though the other seems bigger in size(and they get exactly the same).

They must be looking for food. It appears I was wrong. Sorry brotha.

If you look through a leaf towards a light. does it look like there are pinholes or not quite through pinholes? If so cal def for sure but those leaves don’t look like cal defs that I have seen.

93OG said:

They must be looking for food. It appears I was wrong. Sorry brotha.

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Might be but I do have that cupping and spotting going on so something isn't right. No problem u tried, happy for the input. Though after reading some it seems wind can do this as well? And the worst case of cupping is where its most air going through.

93OG said:

If you look through a leaf towards a light. does it look like there are pinholes or not quite through pinholes? If so cal def for sure but those leaves don’t look like cal defs that I have seen.

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Not exactly sure what u mean? Should It look really white bright light at the size of pinholes? I can check that out next time in there.

What do u think it might be then? P or k def? I know about this time(3-4week flower) ppl usually add a bit of these nutrients

How are you handling the pH? Are you trying to keep it at 5.8 as much as possible?

Ya, like little bright spots, maybe 1/2 mm across.
you might give em a bit of a p k boost. Roots healthy, ph good I assume.
the internets say that cupping is wind burn, I live in Arizona and run a few plants outdoor during the summer most seasons and the only time I’ve seen them cup was when I screwed up my soil mix and made it way too hot. Dirt sucks

polishpollack said:

How are you handling the pH? Are you trying to keep it at 5.8 as much as possible?

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Yes. I PH it to 5.8-6.2 but don't know within the media. Though I feed with ridiculous amounts so it should be OK.