how much gypsum?

[strongbox18]

how much gypsum should i put in each of my holes? im doing an outdoor guerilla grow and the soil has got a little bit of clay my holes are about 2 feet by 2 feet thanks for any input on how much to throw in there, thanks
peace

 

[Ulysses]

Wow! An easy one- a question I can even answer stoned...

How much gypsum? None.

Yes, none. You want Pulverized Dolomite Lime at an application rate of 2 Tablespoons per gallon of soil. Mix very well.

Gypsum is plaster. It doesn't stabilized pH nor does it provide sufficient calcium or magnesium to the plants...

Best of luck!

 

[grapeman]

how much gypsum should i put in each of my holes? im doing an outdoor guerilla grow and the soil has got a little bit of clay my holes are about 2 feet by 2 feet thanks for any input on how much to throw in there, thanks
peace

While the above answer may be correct for indoor container grows in homemade soil mixes, it sounds like you are growing outdoors. We use 5 to 7 tons per treated acre. An acre is 43,560 square feet. so if you are treating say a 3' x 3' area, you just need to do the math. We usually band the gypsum on the surface and let the water take it down into the soil.

Gypsum is almost always good for most soils. You can find out at your local USDA Ag Extension office. Call 'em. your taxes pay their salaries and this is the type of local work they do.

 

[BerndV]

So gypsum is not recommended as an indoor potting mix amendment?

 

[EatMoGrass]

Wow! An easy one- a question I can even answer stoned...

How much gypsum? None.

Yes, none. You want Pulverized Dolomite Lime at an application rate of 2 Tablespoons per gallon of soil. Mix very well.

Gypsum is plaster. It doesn't stabilized pH nor does it provide sufficient calcium or magnesium to the plants...

Best of luck!

When I used gypsum in the past I was using it as a source of buffered sulfur, not as a source of cal and mag. Of course dolomite lime was also used for cal and mag. That was a couple years ago, and I haven't used gypsum since. Not that I wouldn't use it again.

 

[Clackamas Coot]

EatMoGrass

K-Mag has all 3 and is natural/organic in the standard form. That's the wholesale name.

The retail name is Sul-Po-Mag and the generic name is langbeinite.

Check out the numbers here

 

[EatMoGrass]

Thanks Clackamas, those numbers look great and I've read good things about langbeinite. I noticed a couple weeks ago its used in some of the DTE products, although they dont seem to sell langbeinite by itself.
How do you feel about Sulfate of Potash Magnesia? I've been using Espoma brand Epsom Plus for a couple years as a source of Potash,Magnesium,and Sulfur. The numbers on the label are-Potash 22%, Mag 11%, and Sulfur 22%
I'll look around for a source of langbeinite, it will likely replace the Espoma product.

 

[Clackamas Coot]

Thanks Clackamas, those numbers look great and I've read good things about langbeinite. I noticed a couple weeks ago its used in some of the DTE products, although they dont seem to sell langbeinite by itself.

How do you feel about Sulfate of Potash Magnesia? I've been using Espoma brand Epsom Plus for a couple years as a source of Potash,Magnesium,and Sulfur. The numbers on the label are-Potash 22%, Mag 11%, and Sulfur 22%

I'll look around for a source of langbeinite, it will likely replace the Espoma product.

EatMoGrass

Quit looking. Sulfate of PotashMagnesia is langbeinite which is Sul-Po-Mag which is K-Mag. cite

You're there!

CC

 

[EatMoGrass]

Actually I can no longer find the Espoma brand Epsom Plus and my supply is running low. I have also had a very hard time finding glacial rock dust at local garden stores. Store employees have always looked at me like I'm crazy when I ask for glacial rock dust. Funny thing is I live right where the glaciers stopped over South Wisconsin. In fact I once lived on a road called Moraine View Drive. A moraine is formed where a glacier stopped and dumped tons of rock and rock dusts many years ago. So a glacier stopped feet from where I once lived but I cannot find glacial rock dust at any local garden stores.

 

[EatMoGrass]

Yeah I checked the Espoma site and they no longer sell the Epsom Plus product I have been using for over two years now. I never knew it was derived from langbeinite but I immediately knew that I liked the numbers. It was exactly what I was looking for.
When I first found the stuff I was actually buying gypsum for sulfur. The garden center manager who has ran the place for years asked why I was looking for an organic source of mag and sulfur. I responded by telling him that mag and sulfur are two of the three secondary nutrients. He scratched his head for a few moments and said "I think your right, they are secondary nutrients". This guy is brilliant I thought. This was a few years ago but that old guy is still the most knowledgeable employee there. And this wasn't a "hydro shop". This was Jung Garden Center here in Madison. No one seems to know shit round here.

 

[treefrog]

How have you been using the Espoma product?
I've been using Sul-Po-Mag at 1 tsp per gal in my water for about a week now, instead of epsom salts. It won't dissolve well. I might boil water like CC recommended, but what a pita.

The reason I ask is because the website CC linked to says, "Care should be taken when both Dolomitic limestone and Sulphate of potash magnesia are used to avoid excessive Magnesium applications." Is excessive mag possible with Cannabis.. lol

 

[Clackamas Coot]

Is excessive mag possible with Cannabis.. lol

treefrog

Is magnesium levels an issue for many growers?

The reason I'm asking is that for 3 decades I've heard or read the term 'Cal-Mag Lockout' which from what I can surmise is far worse than the 'heartbreak of psoriasis' or perhaps even 'yellow waxy build-up'

What is this 'cal-mag lockout' paradigm? Does the addition of more calcium and/or magnesium take care of this?

Let me know what you know!

CC

 

[Dignan]

I'm interested in that, too. ^^

The one time I had calcium lockout was from allowing my dry cycles to be too extreme. I have no idea how that works, but it was a fairly serious problem to have mid-flower.

 

[EatMoGrass]

I would use a small amount right in my soil mix. I was always careful to not add much because I thought that the sulfur may drop the PH. After reading the link CC posted yesterday I now know the Langbeinite does not drop the soil PH. Because I was considered about the Ph I was using under 1/4 teaspoon per gallon of soil mix. I probably could have used more but I subscribe to the theory that less is better with organics. Once in flowering I would add a little langbeinite to castings, guanos, and lime for a soil top dressing. It wasn't until a week ago that I tried it in a casting/guano tea. I did notice that the aerated tea became foamy after 12-16 hours when it usually takes my teas more like 24-36 hours to become foamy. This probably had more to do with the warmer weather than the langbeinite though.
I just mixed a batch of soil for my hot peppers last night and used a little less than 1/4 teaspoon of Langbeinite per gallon of soil . I would have used more but as I said I'm running low and need to find another source.
I believe the sulfur makes my peppers hot as fuck and buds stink like crazy.

 

[Clackamas Coot]

EatMoGrass

Here's a possible source for you:

If that doesn't work I can give you a phone number to a farm store near me which will sell you whatever amount you need. Same with any other amendment like organic fish meal, organic fish bone meal, crustacean meal, organic non-GMO seed meals, organic seaweed extract, et al.

Far, far less than DTE even if you factor in the shipping costs.

HTH

CC

 

[mad librettist]

Check out my last harvest.

The better yield came off a mix that had gypsum. The bigger container made the bigger yield, IMO, but the presence of gypsum sure did not slow anything down.

 

[EatMoGrass]

Very cool, Thanks CC
I have never seen E.B. Stone or any of the other brands you mentioned yesterday around here. Must be a west coast thing.
No one I know around here knows much about organics. It has always been difficult to find the amendments I'm looking for. I may just know the wrong people.
Although last month Jeff Lowenfels (the author of Teaming With Microbes) was here in town giving a seminar about composting and soil building. The admission was $120 but I did not find out about the seminar until after it was over. $120 was probably too steep for me anyway.
So anyways, yeah CC, give up that phone number for the Sul Po Mag!

 

[EatMoGrass]

Check out my last harvest.

The better yield came off a mix that had gypsum. The bigger container made the bigger yield, IMO, but the presence of gypsum sure did not slow anything down.

Thanks for posting that ML!
When mixing my soil for my hot peppers last night I kept looking at my bag of gypsum and trying to decide if I should add some. Since I am running low on langbeinite I will add some of the gypsum I have laying around as another source of sulfur. The bag I have is 2-3 years old but I'm pretty sure it doesn't go bad. In a couple weeks I be mixing another batch but this time it will be for cannabis.
I got out of the soil building/recycling game a couple years ago when I began having problems do to a toxic Sun Hut offgassing. Now that the offgassing problem if taken care of I'm back to building/recycling my soils.
Basically I'm picking up right where I left off two years ago.
Thanks guys!

 

[mad librettist]

oh yeah, the measurements:

for 1 big trash bag o'soil mix (maybe a cubic foot?)

some fistfuls of gypsum (my hands are on the small side)


lol sorry not too exact

 

[treefrog]

treefrog

Is magnesium levels an issue for many growers?

The reason I'm asking is that for 3 decades I've heard or read the term 'Cal-Mag Lockout' which from what I can surmise is far worse than the 'heartbreak of psoriasis' or perhaps even 'yellow waxy build-up'

What is this 'cal-mag lockout' paradigm? Does the addition of more calcium and/or magnesium take care of this?

Let me know what you know!

CC

Well, I can tell you my personal experience, but I don't have any scientific references to back up conclusions. I'm not actually sure I have any conclusions either..lol Like most here, I'm just a humble guy, trying to grow the best medicine he can. I'll try not to go on too long
There's this balance that becomes trickier and trickier as more parts are added to the equation, and most of us organic folks are like crazy alchemists, adding many different things to our mixes and teas, which is a lot of fun, but makes balance all the more elusive. For many years, I was using tap (city) water, bubbled, with 1/2 tsp of milk of magnesia added to every gallon. I pre-mixed it in big tubs, kinda like Von did with the kal-mag. I was also using ag lime (low mag, high ca) in my mix (lc's, with greensand, but no kelp meal), because that's all I could get. I added maxicrop to all of my water too. I had that system 'tuned'. Fantastic pot!

Recently, I've started collecting rain, because I don't want fluoride, hormones, chlorine etc. in the equation and want a more natural choice for mag too. I'm in the process of finding that balance again. I'm also using azomite in my mix for the first time. I've used it to grow my wheat-grass for awhile and its excellent. I also supplement my own RO water with it.

Anyways, I'm convinced that a very important part of the whole 'cal-mag' equation is nitrogen. I realize that it's commonly known magnesium is needed to process nitrogen. What I mean is that there is a balance (ideally) between mag and nitrogen that goes beyond just needing each other to produce a healthy plant. At times, when I've pushed the nitrogen, I've found more mag is needed to process that nitrogen, whereas the same amount of mag, in a situation with less nitrogen, will cause a lockout. Maybe this is common knowledge and I'm just an idiot! Either way, it would indicate that there is no blanket cure, or general approach to the whole mag issue. Every grower has to find their own balance.

I'm finding that with dolomite and azomite in my mix, I need to add about 3/4 tsp epsom salts to a gallon of rain water to keep a deficiency from showing, while having enough nitrogen to keep them as green as Capt.Cheeze's plants Alright, maybe not quite that green

I just picked up some kal-mag last week and am in the process of finding a balance with that. I'm adding it to my water. I wonder how much mag is in a tsp of k-mag, as compared to a tsp of epsom salts.. and the process continues..

Anyways, is that kinda what you were looking for?

Peace everyone!