How much is too much calcium?

So I've got a 30 gallon batch of soil that has been sitting over the winter with some pond liner over it to keep it moist and prevent rain from saturating it. Every now and then I watered it with some of my fish pond water sometimes with a dash of homemade lactobacillus or em-1... only enough to keep it moist and dark. And every so often I would add some gro-kashi or MBP on top. I'm in the second half of my grow shed build and want to make any corrections to the soil while I still can. It looks and smells absolutely amazing. Dark, crumbly, spongy soil filled with very active mites, springtails and red wigglers. It is the best looking and best textured soil I've created thus far... but will it perform? I know Ca, Mg and K all affect each other and can lock each other out if there is too much of any one input. This soil uses a rather complex recipe with multiple calcium inputs. I've never had my soil tested, and I will be doing that next, but do you think this has too much calcium?

Here is my base:
Peat, 33%
Homemade EWC, 16.67%
Homemade Compost, 16.67%
Pumice, 16.67%
Coco Fiber (not coco peat), 16.67%

Here are my inputs:
Homemade Charged Biochar, 12 cups/cuft
Calcium Bentonite, 3 cups/cuft
Glacial Rock Dust, 1.5 cups/cuft
Basalt Rock (pea-size or smaller), 1.25 cups/cuft
Gypsum, 1 cup/cuft
Oyster Shell Flour, 1/2 cup/cuft
Diatomaceous Earth, 1/2 cup/cuft
Kelp Meal, 1/2 cup/cuft
Crustacean Meal, 1/2 cup/cuft
Alfalfa Meal, 1/2 cup/cuft
Insect Frass, 1/2 cup/cuft
Screened Yard Soil (1/8"), 1/2 cup/cuft
Greensand, 1/4 cup/cuft
Malted Barley Powder, 1/4 cup/cuft
Fish Bone Meal, 3/16 cup/cuft
Neem Seed Meal, 1/8 cup/cuft
Karanja Seed Meal, 1/8 cup/cuft
Mosquito Bits, 1/8 cup/cuft
Sul-Po-Mag, 1/64 cup/cuft

It's hard to say from just looking at your list. And I don't know anything about calcium bentonite. How much calcium does that stuff have? Maybe 3 cups is a lot.

Anyway, the way to know for sure is to out some plants in your dirt! That soil looks pretty loaded, so you should not have any kind of dificency issues for awhile. But if your plants look bad, and are showing signs of any kind of deficiency in the first few weeks you'll know your soil is over-loaded and excessive inputs are your problem.

It's a balancing act. Refer to Mulder's charts...

The other materials you often see cited describe a Ca:Mg ratio as well. I forget the specifics but there's an image I've seen in several threads where there is some discussion on ideal ratios but I don't think it widely agreed upon either. Look for any materials from academia and not specific to cannabis and you'll probably find the science & data behind all of this if you want to dig that deep.

FWIW, I've loaded up my soils pretty damn heavy on Ca and so far can't attribute any issues to the Ca levels.

And definitely get the tests. I value them - at least in my efforts so far I think they helped me.

Thanks guys.

I don’t know if the calcium in calcium bentonite is plant available. My father actually recommended that for aeration.

Yeah, I’m not ready to grow any weed just yet. My shed is almost done, and I’m hoping my soil will be good when the shed is ready so I don’t have to test it with a test plant.

I know the chart , but it doesn’t tell amounts/ratios. Only what affects what.

I’ll do some searching for more information.

I’ve loaded up all my soils with ca and haven’t had a problem (that I could tell) either. I’m just trying to do better each time. Organics was where I started growing many moons ago. But I got lost in the chemical world for far too long. Back to my roots!

And I’ll definitely be getting a soil test. Any you recommend?

Anyone else want to chime in?

I think of calcium as a macro along with npk...

Absolutely, which is why I normally load up my soil with it (and my nutes when I was hydro). I’m just wondering where too much is. I’ve definitely created problems from too much n, p or k as most of us have at some point. I don’t THINK I have with ca. But I have had what I thought we’re magnesium deficiencies which did clear up with epsom foliars, so I guess I don’t really know for sure.

The few guys that have mentioned problems with excess calcium in their soil have also talked about their hard water, full of calcium. And how calcium from the water eventually builds up in the soil.

If your water is cool you might be OK.

Typically 5 ca to 1 mg to .1 fe

that’s what I always Have kind seen with

Was the coco you used in your mix buffered? That would be my only real worry. I've read a few threads about difficulties using peat and coco in a mix together.

Yeah, it was buffered. Good looking out.

It's not your typical coco coir. It's this.
Conibo Organics Fine Grade Coconut Coir 40L - BuildASoil

I rinsed the crap out of it. Removed any particles smaller than 1/4" (a lot of coco peat). Only used the long strands. Soaked in EWC, OSF and pond water for a week before use. They turn into little fluffy balls of strands a little smaller than golf balls that get added to the mix to add aeration. I've had some good luck with it. I stopped using coco peat all together as I find growth in a mainly CSPM mix is superior in my grows.

friedguy said:

Yeah, it was buffered. Good looking out.

It's not your typical coco coir. It's this.
Conibo Organics Fine Grade Coconut Coir 40L - BuildASoil

I rinsed the crap out of it. Removed any particles smaller than 1/4" (a lot of coco peat). Only used the long strands. Soaked in EWC, OSF and pond water for a week before use. They turn into little fluffy balls of strands a little smaller than golf balls that get added to the mix to add aeration. I've had some good luck with it. I stopped using coco peat all together as I find growth in a mainly CSPM mix is superior in my grows.

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i been using long fiber, chunky coco to replace the perlite myself. its working great and is a lil better then perlite in my opinion. The bacteria loves it!

Ok, from what it seems I don't need to worry about the ca in my mix. Plus, I recently sowed in some of the BAS 12 clover crop, so I suppose I can get a decent gauge of how the soil performs based on how the cover crop does... I know it's not cannabis, but any lockout from too much ca should still be apparent. If anyone feels differently, please let me know.

Regardless, I will be getting my soil tested. Can someone recommend a mail in testing facility?

@MustangStudFarm has a place he highly recommends

I've been using the Soil Saavy tests myself, I had started with Logan Labs and weighted scoop mehlich/saturated paste but the Soil Saavy test is more about what is available so it just fits the bill better imo.

The comment re: hard water above is spot on that it needs to be taken into consideration. I think with my high Ca ratios I've been okay but I've also periodically supplemented with things that have Mg in them so that would help with the Ca:Mg ratio angle.

NewGrower2011 said:

the Soil Saavy test is more about what is available so it just fits the bill better imo.

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Has anyone here been to forests or fields where calcareous soils are abundant? Things do seem to grow okay.

Knowing what mineralized nutes are available at any one time via testing I guess would be useful to hydroponic solutions, but anyone tuning the mixing of hydroponic solutions should know already what the concentration is without needing a test, considering the concentration is indicated on the manufacturer's label.

bodhipop said:

Calcium Bentonite is supposed to be awesome. Contains 67 minerals in it or something like that.

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Bentonite and other montmorillonite clay materials aren't useful for supplying minerals in themselves. However they have exceptional caption exchange capacities, and can hold onto saved nutes that would otherwise wash out of your soil or go up your exhaust fan (N). They also have amazing water retention capabilities. Just don't add too much, or you'll make concrete if it dries out. Lol

Best price for food grade calcium bentonite I've found is my local brew store. Forget Amazon on this one.

Northwood said:

Bentonite and other montmorillonite clay materials aren't useful for supplying minerals in themselves. However they have exceptional caption exchange capacities, and can hold onto saved nutes that would otherwise wash out of your soil or go up your exhaust fan (N). They also have amazing water retention capabilities. Just don't add too much, or you'll make concrete if it dries out. Lol

Best price for food grade calcium bentonite I've found is my local brew store. Forget Amazon on this one.

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My bad, I deleted that one before I saw you post. Didn't want to spread info before I knew for sure. So do you prefer this to Basalt or would you say a variety is most beneficial?

Napa has a montmorillonite clay based absorbent, not the DE stuff - was special order at my local store. It's like turface which is another common one I've seen mentioned and I've used in the past. Also certain specific kitty litters are montmorillonite or bentonite based.