Couple grows in, help with identifying issue.

Hey all, I have a couple grows under my belt now but starting to notice a trend. My younger leaves (at time of flip to 12/12) end up spotty and yellow about a month into flower. I can continue on but those leaves are pretty crusty come harvest time. I am using a standard FFOF mix, water is at low 5s ph so I am using ph up to bump it up for every watering. This has happened in my last few grows so I am just looking for advice on what it may be. There is obviously an issue but my yields and product are good. I have had this on multiple strains, just let me know if you need any additional info and I can add more as needed.

Plants (Left is a Blackberry and Right is Supreme CBD) Worse on my Blackberry (which is younger by a few weeks of veg) but still starting to come through on my CBD


Blackberry top view


Blackberry bud, it's not quite that yellow in person, white balance was on auto.


Close up of issue on Blackberry leaf.


Close up of CBD leaf, you can see the spotting and coloring starting but not as advanced as the Blackberry.


Any help is much appreciated, just trying to keep the girls as healthy as I can. Soil PH seems fine, not getting too much light, temps could be a little lower but they stay under 80 and humidity is good. (Average over the last month is 75f and 50%rh) I trained them into a SCROG so they are pretty thick but I have 2 fans moving air around the top and bottom. There are a couple of water spots but not a huge amount so I don't think that is a big problem. Thanks for looking!

Hey what’s the ph in the soil.... you said you checked it right?

Where are you getting your water and how are you measuring the pH? Low 5's for water seems off.

Very rare to see water that acidic.... They just look a little hungry. Start top dressing at the 12/12 flip with dry bloom amendments. Bout a half cup every 2 weeks.

Your plants look a smidge hungry, but the spots are reminiscence of a Ca shortage. If your pH is too low on average, whether it's the soil or the acidic water, your plant's ability to uptake Ca will be very limited. I'd go back and confirm all your pH variables. Good luck.

Thanks all!

Matthewschultz2829 said:

Hey what’s the ph in the soil.... you said you checked it right?

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My run off was in the 6s a couple weeks ago but I will check it again on next watering.

xtsho said:

Where are you getting your water and how are you measuring the pH? Low 5's for water seems off.

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Water is from a well, I have a Hanna Ph meter I am using. Check it straight out of the tap, add ph up, check again and then water / test run off. After the first couple grows the numbers were pretty much the same so I have not been as hardcore on monitoring frequency. All of my calibration juice is pretty old, I should probably order some more and make sure everything is in line.

JoeBlow5823 said:

Very rare to see water that acidic.... They just look a little hungry. Start top dressing at the 12/12 flip with dry bloom amendments. Bout a half cup every 2 weeks.

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Thanks for the tip, I have seen a few mentions of top dressing. I might just throw some more FFOF on for the next watering and look for a specific product to use next.

CannaCountry said:

Your plants look a smidge hungry, but the spots are reminiscence of a Ca shortage. If your pH is too low on average, whether it's the soil or the acidic water, your plant's ability to uptake Ca will be very limited. I'd go back and confirm all your pH variables. Good luck.

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Thanks! I will go back through and test everything again to be on the safe side and look up some info on Ca specifically. Since it is kind of a consistent issue and across strains etc. I feel like it has to be water / soil or some combo.

I will report back if I find anything off. I am watering about 1.5Gal every 2-3 days, just enough to start running out the bottom of 7Gal smart pots. It seems like a lot but I go by weight / feel and plants never looked over/under watered.

420herbalist said:

Thanks all!


My run off was in the 6s a couple weeks ago but I will check it again on next watering.


Water is from a well, I have a Hanna Ph meter I am using. Check it straight out of the tap, add ph up, check again and then water / test run off. After the first couple grows the numbers were pretty much the same so I have not been as hardcore on monitoring frequency. All of my calibration juice is pretty old, I should probably order some more and make sure everything is in line.


Thanks for the tip, I have seen a few mentions of top dressing. I might just throw some more FFOF on for the next watering and look for a specific product to use next.


Thanks! I will go back through and test everything again to be on the safe side and look up some info on Ca specifically. Since it is kind of a consistent issue and across strains etc. I feel like it has to be water / soil or some combo.

I will report back if I find anything off. I am watering about 1.5Gal every 2-3 days, just enough to start running out the bottom of 7Gal smart pots. It seems like a lot but I go by weight / feel and plants never looked over/under watered.

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That's some low pH water. I didn't think it was tap as municipal water sources adjust the pH to be higher.

It's the ph meter.

70's natureboy said:

It's the ph meter.

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I tested it right out of the box, calibrated per instructions with proper solution ( I have done it with 4,10 and 7 ph solutions) and tested again and it was still in the 5s. I have done that multiple times over a couple years. I think I have some Ph strips I could use as a general comparison far a sanity check but I am fairly confident that it is in the 5s. It's well water relatively close to the east coast where water is more acidic so does not seem out of the realm of possability. The Hanna meter I have got good reviews but I would be happy to take suggestions on a better option or other ways to monitor, I am a nerd so I am more than happy to wire more shit up

ooooh, I breezed by that FFOF part. My last couple FFOF plants looked worse than yours. I'm not a fan. Are you feeding them at all? They probably just need some food.

70's natureboy said:

ooooh, I breezed by that FFOF part. My last couple FFOF plants looked worse than yours. I'm not a fan. Are you feeding them at all? They probably just need some food.

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Good to know, I had not been adding anything additional up to the point of posting but I have given some big bloom to the blackberry and just dressed the top of the cbd with more ffof and watered that in tonight. Hopefully they just needed some food, my last grow I started feeding a couple weeks after flip but ended up with some tip burn even with the big bloom which isn't that powerful. Hopefully this will keep it from getting any worse, I should have just started feeding a bit earlier from the sounds of things. I hate losing those sugar leaves but as long as the buds come through that is the main thing Hopefully the next round I will have a better feel for when to start feeding, growing two different strains that started at different times isn't doing me any favors this time either.

Thanks for the input all! fingers crossed they don't get any worse now that I have given them a bit of extra love.

420herbalist said:

Good to know, I had not been adding anything additional up to the point of posting but I have given some big bloom to the blackberry and just dressed the top of the cbd with more ffof and watered that in tonight. Hopefully they just needed some food, my last grow I started feeding a couple weeks after flip but ended up with some tip burn even with the big bloom which isn't that powerful. Hopefully this will keep it from getting any worse, I should have just started feeding a bit earlier from the sounds of things. I hate losing those sugar leaves but as long as the buds come through that is the main thing Hopefully the next round I will have a better feel for when to start feeding, growing two different strains that started at different times isn't doing me any favors this time either.

Thanks for the input all! fingers crossed they don't get any worse now that I have given them a bit of extra love.

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Ive ran 12 at once.

This is only 6.

JoeBlow5823 said:

Ive ran 12 at once.

This is only 6.

View attachment 4624682

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Nice! What size smart pots are those? I am using 7gal but I am in a 3x3. Mine look wider/shorter although I don't have them all the way full.

420herbalist said:

Nice! What size smart pots are those? I am using 7gal but I am in a 3x3. Mine look wider/shorter although I don't have them all the way full.

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5gal 5x5 tent