Black spots just before flushing

This is a West Coast Kush that I just started flush on 2 days ago. Leaves started turning yellow very quickly and did not go to her standard purple hues that I have gotten previously.

Upon inspection of leaves with loupe, I noticed quite a few very small black spots on leaves, but no insects found anywhere. I have been lucky and never had any problems with multiple grows.

Growing medium is a 50/30/20 mix of FF Happy Frog, FF Ocean Forest, #4 Perlite.
Using GH line of nutes. (CaliMagic, Armor Si, Kool Bloom, Micro, Grow, Bloom) at 5.9 pH and 900 ppm. With Recharge between feedings and waterings. 600Watt HPS. Room temps from 70-85. RH around 52.

Any help would be appreciated. Hopefully I can save this plant, as she should be almost ready to harvest.

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The Ocean Forest is kinda hot. I was having ph issues and lockout if above 6.2 in last 2 soil mixes.
So I finally deleted a post without somebody copying it first! LOL

Low pH most likely your problem. I've been growing in ffof with 25% perlite added for 4 years & I'm familiar with the medium.

It's not hot: that's a rumor spread by people who don't know how to feed a plant properly in my opinion.

A fresh bag has a pH in the mid sixes and under 700 PPM. It prefers a pH of 6.5 for best results.

Regardless of feeding pattern at least every 10 days - 2 weeks I run 2x the amount that I normally feed of plain 6.5 water through each plant to drive the salts out.

I check the runoff and I make adjustments if necessary via what I read in runoff.

What is your most recent runoff? Or do a slurry test and post those figures, thats way better than runoff. Also a whole plant picture is necessary.

Also I'd like you to read about Dolomite lime, it is your friend in soil and you should consider augmenting your soil with both Dolomite and perlite going forward, but let's get your numbers straightened out first

regarding the black spots it could be necrotic spots, but it could also be insect poop? I would check carefully for insects or damage
 
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So I finally deleted a post without somebody copying it first! LOL

Low pH most likely your problem. I've been growing in ffof with 25% perlite added for 4 years & I'm familiar with the medium.

It's not hot: that's a rumor spread by people who don't know how to feed a plant properly in my opinion.

A fresh bag has a pH in the mid sixes and under 700 PPM. It prefers a pH of 6.5 for best results.

Regardless of feeding pattern at least every 10 days - 2 weeks I run 2x the amount that I normally feed of plain 6.5 water through each plant to drive the salts out.

I check the runoff and I make adjustments if necessary via what I read in runoff.

What is your most recent runoff? Or do a slurry test and post those figures, thats way better than runoff. Also a whole plant picture is necessary.

Also I'd like you to read about Dolomite lime, it is your friend in soil and you should consider augmenting your soil with both Dolomite and perlite going forward, but let's get your numbers straightened out first

regarding the black spots it could be necrotic spots, but it could also be insect poop? I would check carefully for insects or damage
I will check slurry later tonight when light comes on. I normally flush every 3rd feeding to wash out salts. I have also checked all flowers and leaves for bugs and have not seen any, just these black spots.
 
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Need pics of whole plant. Ph and ec of source water. And how far along is the plant? How often watering? And is the ppm stated .5 or .7 conversion factor. I wish everyone would use ec.

First thought is acidic pot like @Beachwalker but with the runoff coming back at 6.3 plenty of buffer likely left. Likely too high nute buildup.

And i have mostly used ocean forest with 25% added perlite for about 5 years now. I recently tried Potters gold and mother earth groundswell but am back to of.
 
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Need pics of whole plant. Ph and ec of source water. And how far along is the plant? How often watering? And is the ppm stated .5 or .7 conversion factor. I wish everyone would use ec.

First thought is acidic pot like @Beachwalker but with the runoff coming back at 6.3 plenty of buffer likely left. Likely too high nute buildup.

And i have mostly used ocean forest with 25% added perlite for about 5 years now. I recently tried Potters gold and mother earth groundswell but am back to of.
Thanks for commenting. I've never seen Newt build-up raise the runoff pH? ..in my experience it's always lowered it

OP If you're close enough to harvest that you started to flush I'd just do what I'm doing and finish it up
 
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Could be the armor si silica and cali magic raising the runoff ph.
Well I don't know about silica but I do use the calimagic and if I'm honest I was surprised because my pH before I started using Dolemite would sometime hit the low fives or even upper fours! I've never once seen it high and I do check my run off regularly

so I feel something's out of whack with op's numbers? I can't figure out what the hell he's got going on but I think a picture would help? I would just encourage him to finish it out as is because he's very close
 
Need pics of whole plant. Ph and ec of source water. And how far along is the plant? How often watering? And is the ppm stated .5 or .7 conversion factor. I wish everyone would use ec.

First thought is acidic pot like @Beachwalker but with the runoff coming back at 6.3 plenty of buffer likely left. Likely too high nute buildup.

And i have mostly used ocean forest with 25% added perlite for about 5 years now. I recently tried Potters gold and mother earth groundswell but am back to of.
I am at function right now and will get some info replied back when I get to the room and check my notes.

I am 10 weeks into flower, nothing else added except what was stated previously.
While in flower, I try to only do 4 feedings with 1ml of ArmorSi and 4ml of CaliMagic every other nute feeding.
 
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I am at function right now and will get some info replied back when I get to the room and check my notes.

I am 10 weeks into flower, nothing else added except what was stated previously.
While in flower, I try to only do 4 feedings with 1ml of ArmorSi and 4ml of CaliMagic every other nute feeding.
If you're growing West Coast (kush) OG from fastbuds that's an /8 - 9 week flowering plant, you should be really close?
 
Need pics of whole plant. Ph and ec of source water. And how far along is the plant? How often watering? And is the ppm stated .5 or .7 conversion factor. I wish everyone would use ec.

First thought is acidic pot like @Beachwalker but with the runoff coming back at 6.3 plenty of buffer likely left. Likely too high nute buildup.

And i have mostly used ocean forest with 25% added perlite for about 5 years now. I recently tried Potters gold and mother earth groundswell but am back to of.
So, here us what I have.

Tap source: 549ppm with .5 for ec
pH is 6.7
Slurry with 5.9 pH water turned to 6.3pH

Had to pull out of flower room for true coloring on leaves. Noticed a lot of copper and iron coloring on fan leaves.

I also noticed a slight musty smell to the Chernobyl I cut down 4 days ago and noticed the same black spots in a few places on that plant hanging.

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Just dumping a bit of info when looking for purples and other colors in your bud. Anthocyanins don't do as well in cannabis with temps over 70f so lowering the temps later in flower will help bring out the color.

This has nothing to do with your nutrients but thought you may find it useful.
 
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So, here us what I have.

Tap source: 549ppm with .5 for ec
pH is 6.7
Slurry with 5.9 pH water turned to 6.3pH

Had to pull out of flower room for true coloring on leaves. Noticed a lot of copper and iron coloring on fan leaves.

I also noticed a slight musty smell to the Chernobyl I cut down 4 days ago and noticed the same black spots in a few places on that plant hanging.

View attachment 892362View attachment 892363View attachment 892364View attachment 892365
Need distilled water for slurry test
Screenshot_20190901-045330_Google.jpg
 

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