Magnesium deficiency?

I have four Cheese plants going (45 days old) and a couple of them seem to be experiencing some kind of deficiency. Wondering if anyone could help me confirm what I’m looking at in terms of the deficiency and what I can do to help them?

It started a few days ago with yellowing between the veins:

Note: the white specs you see is drywall dust. I cleaned that off. I checked all over with magnification and there’s no evidence of bugs.

I flushed them two days ago, perfect pH, no nutes. I also did an Epsom salts treatment the day before I flushed.

Then I woke up to this this morning on one of them:

This is the closest I found on the chart:

I also tested the water (well water) and found I do have elevated lead and iron levels. I’m trying to figure out how to combat that. I’ll do distilled if necessary, I have 15 plants though so that’ll add up pretty quickly. It’s only the Cheese that this is happening to.

Really appreciate your help, thank you.


What and how often are you feeding?

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@Familyman I did 1/4 power FF nutes a few waterings ago but stopped and the last three have been just pH adjusted water.

You need to up your feeding and use calmag.

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@Familyman Ohh okay I can begin feeding again. The ppms last watering with no nutes were at 1700. Is that too high for nutes though? They’re in a FFOF and FFHF mixture with 30% perlite.

Drywall? Drywall is gypsum also. You should keep the leaves free of this sort of dust or dust of any kind.

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@WickedAle yeah it was an oversight on my part…I had moved them out to finish installing the light rail and sloped floor and the dust must have gone right to them :confused: I did clean them though and they’ll have no dust anymore.

Are the new leaves showing the spots? The dust and the gypsum sprayed leaves won’t improve. You need to focus on the new growth.

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I use this:

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Magnesium sulfate.

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@WickedAle they aren’t, can I remove the damaged leaves without stunting any growth?

@Myfriendis410 thank you!! And so this might be an excess of magnesium?! It would make total sense…they popped up I think the next day after the dust…

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I’d only remove if the leaves were blocking the lower branches. Otherwise the leaves provide nutrition for the rest of the plant through photosynthesis.

Actually I think they are fine; it’s pretty normal to see a few “harlequin” leaves. I could go out and find a couple right now in my grow and they look great. You will see a few squished leaves or ones that are crinkled, color changes etc that are just the plant messing with your head haha.

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Actually, Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. :clown_face::v:

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For some reason I have dyslexia on this! Thanks for catching that. I used large quantities of gypsum in whiskey making and there were other minerals added. Calcium sulfate and Magnesium sulfate (Epsom Salt).

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Easy to confuse. Epsom and gypsum sound similar

Magnesium sulfate commonly called Epsom salt is an inorganic salt with the formula MgSO4(H2O)x

Both containing sulfate SO4 that will be basic (higher pH) in solution —> O’s pulls the H ions in water making them less available.

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@WickedAle @Myfriendis410 that’s all really great info and super interesting, thank you guys so much.

So I’ll start back up with the nutes and worry less about the leaves unless it gets to be a bigger problem. I’m totally cool with that! They’re growing about an inch or so a day so just like yours they’re healthy everywhere else but those few leaves. I’ll sleep better tonight haha


A good couch lock indica helps to sleep too.


It’s my preferred method: a good White Widow or Crystal does me just fine.

@Dex we are familiar with where you are at; the desire to hover over the plants is tough to overcome. You will have a much better time on your second grow because you know what you can get away with better.