Magnesium ppm for manteinance and deficiency?

[JHake]

Hello RIU.

I want to know your opinions on how much ppm of Mg you like on your watering/feedings.

Mel Frank talks about dissolving half a teaspoon of Epsom salts on a quart of water for Mg def.
According to my maths that would be about 250ppm of Mg.

On other part of the book and comparing to other nutrients, Mg concentrations seems to be about 50-75 ppm.

I want to foliar spray some leaves of my plants and don't know which concentration should i use.

 

[myke]

Calmag at 1 ml/l gives 140ppm ish so that’s about 90 Ca 50 Mg. That’s what I foiler feed. So 50- 100 ppm mg sounds right. 250 isn’t going to kill them but it does seem high.

 

[tiltswitch]

What are you growing in? Soiless mixes don't need calmag most of the time, peat based mixes hold nutes well.alot depends on the nutes and your water you use and their levels of calmag.even in coco I often didn't need to add calmag

 

[TintEastwood]

 

[myke]

View attachment 4426121

I assume thats ppm values?

 

[Bernie420]

Hello RIU.

I want to know your opinions on how much ppm of Mg you like on your watering/feedings.

Mel Frank talks about dissolving half a teaspoon of Epsom salts on a quart of water for Mg def.
According to my maths that would be about 250ppm of Mg.

On other part of the book and comparing to other nutrients, Mg concentrations seems to be about 50-75 ppm.

I want to foliar spray some leaves of my plants and don't know which concentration should i use.

When I checked 1 tsp of epsom salt to 1 gal gave me about 250 ppms of mag. I should say mag sulfer = whatever.

I just foliar feed my plants an epsom salt and fulvic acid mix and it kind of jacked up my leaves and that was about 680 ppms I knew it but did it anyways, my bad.

I suggest not to foliar feed above 500 ppms of anything any time now I guess.

It really depends on how healthy and strong the plant is so it can handle it. I have done over 680 on different plants and it didnt jack them up yet that was a different mix of nutrients as well though. I have done 1000 ppms and totally fried them so dont do that.

For you I suggest to folair feed some epsom salt at the 250 ppm range, add a little surfactant and go from there.
Ive never had a problem foliar feeding at below 500 ppms.

and if you want to do some maintenance feeding of mag at the roots to keep things fresh, with your nutes then 75 ppms of that sounds ok to me