ran out of oyster shell flour...

natureboygrower

Well-Known Member
following coots mix plus adding some greensand and alfafa meal(thanks gmm).ran out of oyster shell flour and need to get this all mixed so it can marinate a bit.should i just add garden lime?
 

Wetdog

Well-Known Member
But they do have lime local, right?

My biggest bitch with OSF is the shipping. Some years ago I looked into it. The cost of the product is reasonable, $9/40/50lb bag. The shipping though came to $37 for that $9 product! Not no, but HELL no!

Your liming agent is usually about the cheapest thing in your mix and the reality is, CaCO3 is CaCO3 is CaCO3, no matter the source. That $4.50 dolomite is going to work just as well as that $46 (to me), OSF and why would I pay 10x as much for something that offered no real benefit other than Coot liked it?

Actually, I did try Ag lime (calcitic lime, same as OSF), and went back to dolomite after dealing with constant Mg deficiencys since calcitic or OSF has no Mg in it. Wasn't all that bad in the soil gardens, but in the container mixes it was a royal pain.

Sometimes, the old and simple is still the best.
 

natureboygrower

Well-Known Member
But they do have lime local, right?

My biggest bitch with OSF is the shipping. Some years ago I looked into it. The cost of the product is reasonable, $9/40/50lb bag. The shipping though came to $37 for that $9 product! Not no, but HELL no!

Your liming agent is usually about the cheapest thing in your mix and the reality is, CaCO3 is CaCO3 is CaCO3, no matter the source. That $4.50 dolomite is going to work just as well as that $46 (to me), OSF and why would I pay 10x as much for something that offered no real benefit other than Coot liked it?

Actually, I did try Ag lime (calcitic lime, same as OSF), and went back to dolomite after dealing with constant Mg deficiencys since calcitic or OSF has no Mg in it. Wasn't all that bad in the soil gardens, but in the container mixes it was a royal pain.

Sometimes, the old and simple is still the best.
i agree.am i wrong thinking the garden gypsum im puting in the mix has mg? or is it ca and sulfur gypsum has?just want to note that in case the gypsum already has mg,i'll cut that back to add my lime
 

Wetdog

Well-Known Member
I use gypsum along with the dolo, both at 1cup/cf. Gypsum offers no real buffering ability (wrong form of Ca), but provides Ca and sulfur. I don't "think" it has Mg, but I will go check the bag to be 100% sure. The sulfur does wonders for taste and the extra Ca is always a plus. Even with what's in the mix I usually end up top dressing more later in the grow.

I'll get back on the Mg.
 

hillbill

Well-Known Member
Soft Rock phosphate has about 50% liming effect in relation to dolomite or calcitic limestone, I believe. I like it since I reuse my mix and it is very slow on P release.
Been using 1 tbs of both limestones per gallon of mix
I like to use kmag watering as the nutes are 100% soluble. Great supply of sulfur, K and Mg. Deficiency killer.
 

natureboygrower

Well-Known Member
I use gypsum along with the dolo, both at 1cup/cf. Gypsum offers no real buffering ability (wrong form of Ca), but provides Ca and sulfur. I don't "think" it has Mg, but I will go check the bag to be 100% sure. The sulfur does wonders for taste and the extra Ca is always a plus. Even with what's in the mix I usually end up top dressing more later in the grow.

I'll get back on the Mg.
mg is not a problem with the gypsum i have.just got done mixing up the last of my soil.you are exactly right,i should have used the lime the whole time.$6 for a 50lb bag.thanks for all your help bro
 

Rasta Roy

Well-Known Member
I use gypsum along with the dolo, both at 1cup/cf. Gypsum offers no real buffering ability (wrong form of Ca), but provides Ca and sulfur. I don't "think" it has Mg, but I will go check the bag to be 100% sure. The sulfur does wonders for taste and the extra Ca is always a plus. Even with what's in the mix I usually end up top dressing more later in the grow.

I'll get back on the Mg.
Gypsum is calcium sulfate it only has calcium and sulfur. However...the cool thing about gypsum, the sulfur molecule tends to separate from the calcium one, find bound up molecules of magnesium in the soil and make the highly plant uptakeable magnesium sulfate. This leaves the calcium molecule free to do the same thing with phosphorus, breaking it free of it's chains in soil prison (this is not a proper chemistry term), binding with the calcium and becoming plant uptakeable.

So gypsum doesn't have mag, but it makes the mag and P locked in your soil become more plant available.
 
following coots mix plus adding some greensand and alfafa meal(thanks gmm).ran out of oyster shell flour and need to get this all mixed so it can marinate a bit.should i just add garden lime?
Not the best choice.

Oyster Shell, as with most shells, mostly Calcium Carbonate. Garden Lime is Dolomitic, aka Magnesium heavy vs. Calcium. It will also mess with your pH more than Calcium Carbonate, though your compost in the mix may mitigate this pretty well.

I suggest using Calcium Carbonate, even if you water it in afterwords. Most sources are micronized and thus will migrate pretty good in the media with watering and be available pretty soon to the plants. It is also usually cheaper and more effective.

My opinion and experience.
 

Rasta Roy

Well-Known Member
Seeing as how you have some oyster shell flour in addition to the dolomite lime, you shouldn't have to worry about your cal and mag levels getting out of balance.
 
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