Open to suggestions with my magnesium issues

[Rama777]

Yo! I’ve gotten some advice on what to do, but I’m always happy to get multiple diagnosis, even if in the end I end up even more confused :/

Plants are 6 weeks old. Ppfd is a touch under 200. I’ve tried taking it higher. It’s possible they could handle it but I want to straighten out the mag issue first.

RO water with calmag. Started off very tiny, have worked up to 250ppm on the last watering. Worth noting that the mag symptoms have worsened since that last watering with the higher ppm. So I’m not feeling like attempting to boost those numbers even higher.

No feedings yet. Soil was too hot. Created some stunting in the beginning. Little by little they are getting over that.

VPD 1-1.1

Leaf Surface Temps - as low as 70, as high as 78. Haven’t seen any difference regardless of temps.

Overwatering? I don’t believe so.

The more obvious answer is to foliar feed them epsom, or to add it into the water.

If I do add it to the water, skip the calmag or reduce it and supplement with some epsom?

If foliar, how often until symptoms seem to be resolved?

And if directly in water, alone or with calmag, how often until symptoms clear? Or in other words, roughly how long does a single corrective feeding take to offer visual feedback of its efficacy?

Oh and also, while this isn’t totally consistent across all the plants, I feel like it’s MORE isolated to the upper growth. I’ve read that being mobile, mag deficiencies start by pulling from the older leaves to keep the upper leaves happy. Since I’m not so sure that’s even happening, it does make me question wether or not I have a true deficiency, or some other imbalance.
Thank you fine people!!

 

[LoveGrowingIt]

how often until symptoms clear? Or in other words, roughly how long does a single corrective feeding take to offer visual feedback of its efficacy?

I definitely would give that plant some Mg. From what I've seen and read, yellowing (chlorosis) usually doesn't improve if there's no green left. The plant should have a healthier overall appearance, though.

 

[Rama777]

I definitely would give that plant some Mg. From what I've seen and read, yellowing (chlorosis) usually doesn't improve if there's no green left. The plant should have a healthier overall appearance, though.

Thanks man. Gonna do that today. If this were your plant, would you do epsom isolated or add it into your calmag?

 

[Rama777]

Other thing because I’m so damned mathematical minded to a fault is how much ppm of empsom to use as a corrective.

Many say as high as a tablespoon. Well turns out a tablespoon of epsom is like 1800ppm or something. Can’t remember. I just put an eighth of a teaspoon into a gallon and it boosted the ppm by 175. That’s still more mag than they need on an ongoing, every water basis, which makes me think it’s probably enough. But I’m open to bumping that up to 350, or 525 or whatever. A single half teaspoon of epsom to a gallon would be about 700ppm. Seems like overkill but this is totally new to me..

 

[MrGreenfinga]

Other thing because I’m so damned mathematical minded to a fault is how much ppm of empsom to use as a corrective.

Many say as high as a tablespoon. Well turns out a tablespoon of epsom is like 1800ppm or something. Can’t remember. I just put an eighth of a teaspoon into a gallon and it boosted the ppm by 175. That’s still more mag than they need on an ongoing, every water basis, which makes me think it’s probably enough. But I’m open to bumping that up to 350, or 525 or whatever. A single half teaspoon of epsom to a gallon would be about 700ppm. Seems like overkill but this is totally new to me..

Heard alot of good things about it never tried it though but you may also consider if there is something else locking out the Mag just a consideration

 

[Rama777]

Heard alot of good things about it never tried it though but you may also consider if there is something else locking out the Mag just a consideration

Yeah I’ve thought about that but can’t actually figure it out if so. Water ph is always good. Nutes are a little hot in the soil (not feeding them yet..). Ultimately I doubt it, unless adding calmag at 200ppm to my RO in general would be causing an excess of calcium. Kinda doubt it. Seems rather likely it’s a mag deficiency..

 

[MrGreenfinga]

Yeah I’ve thought about that but can’t actually figure it out if so. Water ph is always good. Nutes are a little hot in the soil (not feeding them yet..). Ultimately I doubt it, unless adding calmag at 200ppm to my RO in general would be causing an excess of calcium. Kinda doubt it. Seems rather likely it’s a mag deficiency..

Maybe it could be excess potassium
That also tends to lockout mag if the plants still small and not in flower could be it maybe?

 

[Rama777]

Thought about that too. As for what’s in the soil, the base NPK is probably in the 4-2-1 range, maybe 5-3-1 or something. Shouldn’t be imbalanced towards potassium for any reason.

 

[ArtfulCodger]

I'd turn the light down.

 

[Bilber]

Soil...........this is not my territory......always scanning to learn.....

Soil can take at least a week to recover.....but it depends on whether it's quick/instant, or if it takes time to absorb/intake......

Soil........it's tough but very rewarding......

 

[MrGreenfinga]

I'd turn the light down.

Totally agree here too much light could be your issue too

 

[Rama777]

I'd turn the light down.

Yeah I’ve thought about that too..

Pretty sure they’re getting about 175-190ppfd. Not opposed to turning it down, just seems likes being 6 weeks old today that I might not need to consider that?

 

[Imzzaudae]

What mineral additive are you using to replace micro nutrients stripped from R.O water?
As you have given this plant Epsom salts or cal-mag. I'm not sure your issue is Magnesium. I'm thinking possibly light burn as the lower leaves seem to be OK. Leaves look quite washed out from to much light. What light are you using and how far above plant tops? Power setting?..

What medium is the plant in, what you feeding? How much, how often?
You can top dress with a teaspoon of Dolomite lime and a teaspoon of Gypsum.
This will take care of Calcium, Magnesium, Iron and a few others for 3 or 4 months.
Do it again when you flip.

 

[Bilber]

Leds are powerful.......more than I thought......mh/hps......easy, well, easier maybe.....I run both.....still adjusting the led.......

 

[LoveGrowingIt]

Thanks man. Gonna do that today. If this were your plant, would you do epsom isolated or add it into your calmag?

I mostly use Epsom salt for Mg and gypsum for Ca. In this case, I'd just use Mg and keep an eye on it till the plant is healthy.

 

[Rama777]

What mineral additive are you using to replace micro nutrients stripped from R.O water?
As you have given this plant Epsom salts or cal-mag. I'm not sure your issue is Magnesium. I'm thinking possibly light burn as the lower leaves seem to be OK. Leaves look quite washed out from to much light. What light are you using and how far above plant tops? Power setting?..

What medium is the plant in, what you feeding? How much, how often?
You can top dress with a teaspoon of Dolomite lime and a teaspoon of Gypsum.
This will take care of Calcium, Magnesium, Iron and a few others for 3 or 4 months.
Do it again when you flip.

Roots organic calmag. Derived from keserite and gypsum. No nitrigen in it.

Medium is super soil, peat based, some coco.

I have not fed them anything besides Calmag, every watering, between 100-150 though last time was 250ppm. Leaves are dark from the soil being somewhat too hot for them out of the bag. Also have not given them epsom at all to date.

Light is a Migro, 125 watts, set to 60% at 30” distance.

Though I had brought it closer, but not by much. Was doing 5% increases daily and got up to maybe 240ppfd but then backed off again after topping. So it could be mostly light stress..?

 

[Rama777]

I mostly use Epsom salt for Mg and gypsum for Ca. In this case, I'd just use Mg and keep an eye on it till the plant is healthy.

How much epsom do you use if you’re workin’ on a deficiency?

 

[Pilted]

Looking at the plant the over all color looks good, so that rules out a lot. The edges of the leaves are showing burn so that suggest over feeding. You said your not feeding and soil is hot, so that kinda explains that. Over all structure of the leaves on the plant are not flat or slightly praying, this indicated you have too much light on them. I don't see a mag deficiency, but I am old and color blind, so better pics would be helpful.

 

[Rama777]

Looking at the plant the over all color looks good, so that rules out a lot. The edges of the leaves are showing burn so that suggest over feeding. You said your not feeding and soil is hot, so that kinda explains that. Over all structure of the leaves on the plant are not flat or slightly praying, this indicated you have too much light on them. I don't see a mag deficiency, but I am old and color blind, so better pics would be helpful.

Agreed about the lay of the leaves. They were laying flat actually until I did the topping. Possible thy needed reduced light intensity from that for longer than I thought.

Okay sounding like maybe bump the lights up and give it a few days. BUT, by not adding extra mag to the soil I am not doing anything to correct the missing mag from the leaves currently.

So perhaps a one time foliar to help the leaves out and avoid upsetting the soil?

 

[Pilted]

That leaf showing signs of nutrien imbalance. Maybe mag, but I think more likely the soil being hot is causing multiple issues. Signs of nutes burn and signs of deficiencies, sounds like the soil is just all over the place.