Running into a little deficiency over half way therw flower

[Edna]

Hello folks,
I’m almost at the start of week 6 flower. 40 days into to be exact. I’m am starting to see a cal mag deficiencies. Only on a few leaves on two of my girls (4-5 fan leaves).

2 solar system 550s
Rh is 45-50
Temp is 76 during the day 68 at night
FFOF with 35% perlite
Always ph fed at 6.3
Ppm 800-900
Fed with advanced nutrients
A-B bloom
Cal mag
Overdrive
B-52
(As of right now)
I am currently fallowing the schedule from the website.

These girls have been on a rollercoaster from the start. I know for a fact there could be a lot of salt build up in my soil. Im at a feed water feed schedule at the moment. With calmag mixed everytime (feed and water) at 1ml per litre, using 6 litres H2O till run off at 5-10 %. Drying out every two days. I know the led lights I am running could factor in a huge part of why I’m seeing this deficiency. Would you guys recommend upping the cal mag douse? According to the strain (crown royale) flowering period is 9 weeks, give or take the trich development. Cheers guys all input in appreciated! I’ll add some pictures.

 

[Old Salt]

It looks like pH fluctuations or a phosphorus deficiency.

Are these the lower leaves, and do they feel stiff? If so it's probably a phosphorus deficiency. Phosphorus is used for flower development, so that ties in with your stage of growth.

Tan or brown spotting on the lower and middle leaves usually indicate pH fluctuations. You are checking the pH and maintaining it at 6.3 so this is unlikely. Do you check the calibration of your device regularly?

 

[Captain Cannabis]

Here's a handy little graph below, I like to use. For my current grow in FFOF, I've found that 6.5 is the sweet spot for MY plants. Different strains could vary I suppose.

 

[Edna]

It looks like pH fluctuations or a phosphorus deficiency.

Are these the lower leaves, and do they feel stiff? If so it's probably a phosphorus deficiency. Phosphorus is used for flower development, so that ties in with your stage of growth.

Tan or brown spotting on the lower and middle leaves usually indicate pH fluctuations. You are checking the pH and maintaining it at 6.3 so this is unlikely. Do you check the calibration of your device regularly?

Thank you oldsalt for replying, actually these leaves very from middle to top of my plants. Correct they are stiff, and yes I use a bluelab ph pen calibration is done every week. I was wondering should I try to ph a bit higher? Make it more accessible for phosphorus to uptake ?

 

[Edna]

Thanks captain, I’ve reviewd that chart like it was my bible. Hah

 

[Captain Cannabis]

What type of water do you use? I ask, because I had an issue AN's ph perfect, and my well water. No matter what ph I got it to, it dropped below 6. Not saying that's your issue, I'm curious about the info.

 

[Edna]

What type of water do you use? I ask, because I had an issue AN's ph perfect, and my well water. No matter what ph I got it to, it dropped below 6. Not saying that's your issue, I'm curious about the info.

I was just going threw your journal, and yes i was just about to ask that same question. I use bottle water from my local store. Ph is 6.8. I add a little down to it on watering day to reach that 6.3, and when I mix feed I use the ph up. Do you think the AN ph perfect is fighting the soil buffer ? When I first got into growing I never even realized I bought the ph perfect. That could be why I’m seeing the phosphorus deficiency?

 

[Captain Cannabis]

I was just going threw your journal, and yes i was just about to ask that same question. I use bottle water from my local store. Ph is 6.8. I add a little down to it on watering day to reach that 6.3, and when I mix feed I use the ph up. Do you think the AN ph perfect is fighting the soil buffer ? When I first got into growing I never even realized I bought the ph perfect. That could be why I’m seeing the phosphorus deficiency?

It could be the issue. It was for me. Try mixing up a small batch of feed, ph it, and let it set for a couple of hours. Then check it. See how far it goes.

You could also try a slurry test of a small portion of your soil, just to see what your actually getting to the roots.

 

[Edna]

It could be the issue. It was for me. Try mixing up a small batch of feed, ph it, and let it set for a couple of hours. Then check it. See how far it goes.

You could also try a slurry test of a small portion of your soil, just to see what your actually getting to the roots.

I tried a slurry test on FFOF just by itself, not thinking of how the an ph perfect would affect it. I believe it came out to 6.7, if i recall correctly. I would Basically do a slurry test after I feeded threw the soil? Would this be the way you would go about it ?

 

[Captain Cannabis]

I tried a slurry test on FFOF just by itself, not thinking of how the an ph perfect would affect it. I believe it came out to 6.7, if i recall correctly. I would Basically do a slurry test after I feeded threw the soil? Would this be the way you would go about it ?

Yes.

 

[Edna]

Yes.

I will keep you updated captain, hopefully we can get to the bottom of this. In the mean time hopefully someone has some input on to how to deal with the deficiency. Going to be tough if I’m fighting that ph perfect buffer. If it is phosphorus I’m lacking which makes sense in flower, maybe ill try to feed at 6.5 6.6 ish to make up for that drastic drop from the ph perfect.

 

[Edna]

The problem is worsening. It baffles me because it’s only on one main cola, and it’s only affecting the top. Is this what happened to you @Captain Cannabis Cannabis ? I’ve narrowed it down to two things, ph fluctuations are right out of whack, or locked out nutrients. @Emilya would you care to chime in one more time ? I understand my poor choice of nutrients might be a leading cause in this matter, but why just one cola ? Also, do growers flush salts out this late in flower? I’ve been researching deficiencies, and only found a couple looking like mine. Most threads say cal/mag issues. Hopefully this problem doesn’t get too out of control, as I’m almost nearing the finish line. I’ll throw a couple more pictures of the affected cola on asap..

 

[Captain Cannabis]

Yes, that's almost identical honestly. I wish I had taken a pic of the leaf below, before I plucked it. The little brown/rust spots caught my eye first, and that's when I began investigating my PH problem, as mentioned in my journal. The leaf eventually looked just like the one in your photo above, as it took the missing Calcium/Magnesium from the leaves. Also, my leaf was near my fresh air intake and it was on that side only, that I saw damage.

After I found the problem, I flushed my soil with 6.5 RO water with Calmag. I used 2 gallons per gallon of soil. The symptoms cleared after a few days, but the damaged leaves were goners. However, this was in veg, so I'm not sure how it would effect the plant close to harvest. I personally think, if I were in your shoes I'd flush them, just so it doesn't progress.

 

[Edna]

Thank you @Captain Cannabis. Flushing them stopped the progress of the deficiency, harvest should be knocking at my door in the next week or so. Nonetheless it has been a learning curve, and I do believe these girls will make it. Thanks for all the information you provided I still personally believe it has something to do with the ph perfect nutrients. Feeding at 6.5 now, and flushing this week. Cheers Edna

 

[SlyTown420]

So nice to hear that the flush solves this one.

 

[Captain Cannabis]

Thank you @Captain Cannabis. Flushing them stopped the progress of the deficiency, harvest should be knocking at my door in the next week or so. Nonetheless it has been a learning curve, and I do believe these girls will make it. Thanks for all the information you provided I still personally believe it has something to do with the ph perfect nutrients. Feeding at 6.5 now, and flushing this week. Cheers Edna

That's great! Happy to hear it cleared up. I also believe it has something to do with ph perfect. I hope you enjoy your harvest, and wish you luck!