Does she need Cal-mag - day 43 from12/12

Hi all,

I thought things were going along ok and then some tips curled up and various leaves discolored pretty quickly. Based on the leaf color chart that goes around it looks like mag to me, but this is my first grow so you all know better! She’s about 66 inches and has been healthy all along. I hope I didn’t do something irreversible.

Strain: MK ultra
Nutes: Fox farm trio, Rhino skin, FF Microbes, Sledgehammer (last flushed at flip)
Last feed day 42, Wed. 5/18 - 2 gallons, 6cc rhino skin each
h2o in - 187ppm, 6.9 ph
Out: 1040ppm, 5.8ph

Feed before was day 39, Sunday, 5/15 got 2 gallons with 1/2 FF trio and rhino skin.
In 840, 6.7ph
Out 1360, 5.9ph

I wait until they are dry and light before feeding again.

Light is a Kind x420
PPFD is between 800 and 950 at the tallest colas

Temp stays between 75 and 85, humidity 55-60%.

Thanks in advance for your thoughts all!!


Looks like Mag deficiency. No worries about adding Cal-Mag, it is very well tolerated by the plant. Near zero chance of hurting it with that.

You have some big colas on those ladies. It’s going to be a happy harvest :face_with_spiral_eyes:

I’m assuming soil is your medium? If so that PH of 5.8 and 5.9 could be preventing nutrient uptake. That’s a great coco PH. The PPMS look great :love_you_gesture:

Thanks,I’ll add some cal-mag and report back. Should I trim off all of the affected leaves??

Of course I’ll report back on the colas too, I wouldn’t have any if it weren’t for you all!! :partying_face:

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You can pluck the effected leafs if you want to.
Any leaf parts that are dead isn’t doing anything, but the parts that are green still photosynthesis…

So really just a matter of preference, unless you think some will die off into the bud and cause rot or mold… then they got to go :sweat_smile:

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The 5.8ph runoff could be the issue as calcium, magnesium and phosphorus can be locked out that low in soil.

Im not saying this is lockout, im just saying that it could be, if giving some calmag doesn’t stop the issue, i would look into trying to up the soil ph.

Or some good microbes can over come wonky ph levels sometimes as they can make things more available to the plant and feed it at a wider ph range…
You got this though my freind :grin:


Thank you for all the tips!! She seems happy again, on day 47!!


I was wrong @beachglass, @OGIncognito, @1HappyPappy, @HMGRWN, she seems to be sicker and I’m not sure what to do. The leaves got yellower and yellower.

The next day, (44), cal-mag went in. She had 1 1/3 gallons in @6.9, 308ppm, out in the pan was 5.8ph, and one ppm reading was 1600. Another was lower at 1150 so I thought it was a bad reading the first time.

Day 48 (Tuesday) the pan was bone dry. I gave 2 gallons in at 7.05ph (with .5cc ph down), 185ppm, out was 5.9ph and 915ppm from the pan right then. Two hours later from the pan was 5.7ph, 1330ppm.

I decided to flush yesterday to get the ph up. I gave 6 gallons with Sledgehammer. The ppm came down to high 300s. Yesterday the ph in pan finally went to the low 6s at around gallon 4 and I thought to the middle 6s by the end.

However, today (day 50 from 12/12) the pan is dry. I was able to get about 6ml sucked up from the bottom. The PPM is fine and low low, but the damn ph read like 5.9 again. There wasn’t enough to really submerge the tips, but it seemed ok enough for a reading

The measuring gear is an Apera ph60s and a TDS EZ. The water before anything tested the same every time. I’m not sure what my next step should be or when, thoughts?? Thank you in advance for the help!!

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:point_up_2: is this your run off catch pan and if so do your pots sit in the run off?

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Those PPMS look good for soil, the PH is low and might be making certain nutrient uptake difficult, if your pots are sitting in the run off it will get wicked back into the medium and root mass. Run off is important to rinse the un-used fertilizer away from the previous feeding and if not discarded will get absorbed and create issues :love_you_gesture:

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Thanks - yes, for run off. They sit on a brick so maybe 3” up. The bricks are higher than the pan so it runs out before the pot can really sit it. I suppose if the roots are out the bottom, I haven’t looked for that. You think that might the issue?

What should I do for all of these leaves, trim it all if no green?


Yes you can remove the yellow leaves, they won’t recover. Seeing as you just flushed, I would feed nutrients factoring in the run off PPMS to hit a 1000 and go in with a PH of 7.0 and check the run off to see if the PH is in the 6.2 -6.8 range. :love_you_gesture:

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A top dressing of dolomite lime tilled in about an inch below the surface will help raise and stabilize the PH :love_you_gesture:


Thanks @OGIncognito - the bricks were higher than the pan, but the middle of the pot sagged down into the runoff for sure. Your analysis was spot on. All three ladies too. It doesn’t really look like there are visible issues with the GG or Blue Dream, but I’m flushing those anyway because the values are not quite right.

I’m at day 52 of 12/12, 45 of flower, you think that can be the last flush if all else stays ok? I’m hoping to give a couple more feedings and then just water. 1st grow, I didn’t plan for easy flushing correctly, it’s a massive pain in the butt. Totally fine of course, but I’ll leave it at the fact that a grocery store turkey baster is the main tool for getting the runoff out… :partying_face: :rofl:

:point_up_2: been there :joy::joy:. Flushing with a higher PHd water would be a reset to get the soil PH back in the 6.5 range. When you do this make sure to catch and test the last bit of the run off, factor those PPMs with new nutrients to equal a 1000 PPMs and PH between 6.2-6.8 :love_you_gesture: