Just How Common is Magnesium Deficiency in Soil/Soil-less?

[Jimster]

Just how many growers have ever had a magnesium deficiency that have grown using a soil or soil less type of growing medium, like Coco, Promix, Fox Farms, potting soil, or any other dirt substitute? I have never had the need to use any magnesium supplements and I don't really use too much other than general nutrients and a few soil amendments... wood ashes and compost/manure. I use regular tap water, which is about 200ppm on avg.
I see so many posts about using Cal-Mag that I wonder if it is all really necessary. I understand that using RO water will remove some of the minerals from the equation, but how many have actually had verified magnesium deficiencies? It is used like holy water on Halloween in some circles, so I was wondering what, if anything, I was missing. No urban canni-legends, please, just actual experience.

 

[Dirtbag]

Never.

 

[BCgrower420]

Dealt with it while using potting soil but it only effected one strain, gave that strain cal mag and it fixed it. Never used it prior or since. That's while I was using advanced nutrients micro, grow, bloom. Strain was blue dream autoflower.

 

[MIMedGrower]

I have had an aging mostly full bottle of Botanicare Cal Mag plus for years now.

Just made the problem (which was roots blocked by excess nutrients) worse in only a couple applications.

I learned to leach when necessary and monitor my runoff for trends. The nutrients are plenty with potting soil like ocean forest or the like. Plus i use well water with .3 ec (150 ppm). And pure blend pro grow which has proven to be complete in my garden. No need for calcium , mag or iron and the other trace minerals included in cal mag plus.

 

[Aqua Man]

Had some minor deficiencies. More so calcium. If your using RO it removes pretty much every mineral. On my RO unit which I don't use on my grows since my tap is good my ppm is 1-2. That's RO/DI. So it's a must unless your ferts contain adequate amounts. With my tap I use half dose generally.

I would think this is not near as common in soil as it is soiless. In the promix soil mix you gave me I use none and have not had any issues. In my hydro system its a different story but both are also under different conditions and I'm sure growth rates have something to do with it.

 

[Jack og]

In coco with well water , we maybe use calmag once every 6th watering . Usually the leaves will tell ya and most nutes have ample macro minerals and our well water is chock full of calcium and magnesium due to deep sand layer.

 

[MIMedGrower]

In coco with well water , we maybe use calmag once every 6th watering . Usually the leaves will tell ya and most nutes have ample macro minerals and our well water is chock full of calcium and magnesium due to deep sand layer.

I havent tried coco alone but thanks for that info. I always read to supplement regularly and that doesnt sound right with nutes and well water to me.

 

[Beachwalker]

I ran into a legitimate mag deficiency once in 4 years of growing in ffof when I switched to the old formula Megacrop

 

[Aqua Man]

I ran into a legitimate mag deficiency once in 4 years of growing in ffof when I switched to the old formula Megacrop

That's what I'm using. Gotta say I love it though and still have a crap ton left. I have heard the new formula has no issues with this.

 

[Jack og]

I havent tried coco alone but thanks for that info. I always read to supplement regularly and that doesnt sound right with nutes and well water to me.

Our water sucks bad here, in the valley it’s surrounded by Ag and well how much of the crap they use makes it to the water table is worrisome, the water did not test well. Heck we call it non potable as it’s not drinkable , thank god we are putting us a massive RO system. The plants will love it but then the age ol question of to calmag or not to calmag arises again! Lol

 

[Mr.Juice]

On my very first grow with some autos I was using regular tap water ( ~370 ppm, I didn’t know this at the time till much later when I got my meter ) and the water is super hard here. I live close to a limestone quarry. Straight promix HP, nutri + line of nutrients. Had no difficulties during veg, if anything as I think back I was probably putting too much as they were fairly dark green. Then I fucked up the grow during flower lol.

Being new and stupid, reading too much and talking to a friend, I was told I HAD to go to RO, so I did. Got the tds meter as well as the RO filter and when I tested I was down to 7 ppm. Still under the same setup, second grow, same seeds. This is what happened, so yeah I think I definitely had a deficiency

 

[Beachwalker]

That's what I'm using. Gotta say I love it though and still have a crap ton left. I have heard the new formula has no issues with this.

Great company! Greenleaf used to be over on roll it up a lot until they kicked him out when they got a better offer from some other overpriced newt company, can't remember who it was right now

Any company that gives free samples is ok! Also they listen to their customers and changed the formula too. I'd order from them again in a minute!

 

[Aqua Man]

Great company! Greenleaf used to be over on roll it up a lot until they kicked him out when they got a better offer from some other overpriced newt company, can't remember who it was right now

Any company that gives free samples is ok! Also they listen to their customers and changed the formula too. I'd order from them again in a minute!

+1 I have no intention of switching once I need more.

 

[BigCube]

Just how many growers have ever had a magnesium deficiency that have grown using a soil or soil less type of growing medium, like Coco, Promix, Fox Farms, potting soil, or any other dirt substitute? I have never had the need to use any magnesium supplements and I don't really use too much other than general nutrients and a few soil amendments... wood ashes and compost/manure. I use regular tap water, which is about 200ppm on avg.
I see so many posts about using Cal-Mag that I wonder if it is all really necessary. I understand that using RO water will remove some of the minerals from the equation, but how many have actually had verified magnesium deficiencies? It is used like holy water on Halloween in some circles, so I was wondering what, if anything, I was missing. No urban canni-legends, please, just actual experience.

I agree. It's way overused. Most people dont need it. Because my water out of the tap is 12ppm, I use .5 ml every feeding. That's a quarter of the recommended amount.

Now I'll be the first to admit that I might not need it at all. I never needed it in dwc, nor in dirt. The only reason I use it now is cause this is my first time in coco, and everyone says I need it. Lol

I'm sure I could go without it. Next time around I won't use it just to see what happens. I'm sure I'd be fine without it.

 

[MIMedGrower]

+1 I have no intention of switching once I need more.

I got a free sample of new megacrop. That stuff is ridiculously over ammended with every mythical weed additive in my opinion.

Not sure how they can get silica and calcium to become reliably soluble but i dont like it. And bennies too. I dont want all that crap going in my plants every feed. Talk about possible nutrient conflict.

 

[Aqua Man]

I got a free sample of new megacrop. That stuff is ridiculously over ammended with every mythical weed additive in my opinion.

Not sure how they can get silica and calcium to become reliably soluble but i dont like it. And bennies too. I dont want all that crap going in my plants every feed. Talk about possible nutrient conflict.

I haven't seen a scrap of precipitate and it mixes very easily imo.

I'm curious though what you don't like about bennies? I mean I guess if your running sterile? I do think the industry has a lot of learning to do on them especially the difference in hydro and soil. I don't think it has bennies in it at least I never noticed that it had

What's in it you don't want every feed?

 

[MIMedGrower]

I haven't seen a scrap of precipitate and it mixes very easily imo.

I'm curious though what you don't like about bennies? I mean I guess if your running sterile? I do think the industry has a lot of learning to do on them especially the difference in hydro and soil. I don't think it has bennies in it at least I never noticed that it had

What's in it you don't want every feed?

All of it except NPK and calcium and trace elements.

Every other ingredient should be only supplemental in my opinion. Why spam an accumulator plant?. I give only what they need hopefully.

But of course if it works and your happy i have no argument. Just my opinion.

 

[Aqua Man]

All of it except NPK and calcium and trace elements.

Every other ingredient should be only supplemental in my opinion. Why spam an accumulator plant?. I give only what they need hopefully.

But of course if it works and your happy i have no argument. Just my opinion.

Fair enough we all have our preference was just curious if you seen something I didn't. I feel it's very beneficial for the system I run at an extremely reasonable price. I have heard complaints of it causing some build up in sterile hydro systems. I am assuming due to some organics.

After many years in the aquarium hobby I think people in hydro growing cannabis have either very poor knowledge of live systems and how to maintain them also how much more stable they are once established although the initial setup can take a very long time. Or just very little patience.

I mean current practice of res changes shows exactly my point. I mean how would the dirt guys feel about changing out all thier dirt once every other week of more. Talk about not giving your microbes a chance to populate and do their jobs.

Anyhow I won't go on and on in this thread but to many people are just of the plug and play mentality. That's just not the case with live in hydro.

 

[MIMedGrower]

Fair enough we all have our preference was just curious if you seen something I didn't. I feel it's very beneficial for the system I run at an extremely reasonable price. I have heard complaints of it causing some build up in sterile hydro systems. I am assuming due to some organics.

After many years in the aquarium hobby I think people in hydro growing cannabis have either very poor knowledge of live systems and how to maintain them also how much more stable they are once established although the initial setup can take a very long time. Or just very little patience.

I mean current practice of res changes shows exactly my point. I mean how would the dirt guys feel about changing out all thier dirt once every other week of more. Talk about not giving your microbes a chance to populate and do their jobs.

Anyhow I won't go on and on in this thread but to many people are just of the plug and play mentality. That's just not the case with live in hydro.

Wonder if mega crop was tested for bacteria counts in oregon like the stand alone bennies?. Most of those have nowhere near the advertised count.

Now i went and messed you up. :-)

Oops.

 

[Aqua Man]

Wonder if mega crop was tested for bacteria counts in oregon like the stand alone bennies?. Most of those have nowhere near the advertised count.

Now i went and messed you up. :)

Oops.

Bahaha right, I hear that. I mean I have my own so unlikely they would colonize and be out competed anyhow. But I do like they have some good food sources for them in it. Not that they need much.

Personally if you set your hydro up right (not a fast process) and look after it (much different practices than current norm) there is not need to add any bennies to your system, they occur naturally.

I'm doing some testing on some of this now so far no issues and I cannot foresee any. But I would not feel comfortable encouraging others to due so without a decent understanding.

Honestly the most plug and play method is sterile. But then again you don't learn from not doing


Added: the majority of bennies added don't do well in hydro and need to be constantly resupplied. I keep hydrogaurd on hand only for the purpose of treating pythium if that happens since the particular strain used in it has been shown for many years to kill pythium in agriculture