For what it’s worth, our (city) water is pretty ok… soft. About 0.1 EC.
Thanks @ColeLennon, I was being lazy.
So it’s just a high quality Calcium Sulfate then I guess (or “Gypsum”). Like I mentioned in first post, GreenGenes started using Calcium Sulfate recently (in coco) so he could get off the CalNit later in flower. Not that using Calcium Sulfate is new.
Thanks.
That’s what mine is at too, and especially when I run coco (which is almost always), I can hit deficiencies. Calcium sulfate is a good choice. It’s not going to run up your pH. I’m not certain it’s reservoir compatible though, but if you’re using coco or peat, you can pre-mix it in the media.
I have some diamond k, but I’ve only used it outdoors – not in a tank solution. But probably someone here has tried it and would know.
Calcium chloride is fully soluble ~34% calcium. 0.5g/gal provides 43.5ppm of Ca and 78ppm Cl. I would probably limit to at most 1g/gal or you could see negative effects. Gypsum is good choice though if it works for your application. I don’t know how much sulfate is a toxic level, but it’s quite a lot.
Calcium Sulfate (gypsum) isn’t very water soluable but I think the limit is like 7g per gallon. So won’t really work in a stock/concentrated solution but if adding directly to a nute tank you should be fine. Most recipes I see call for 1-2 grams per gallon.
I grow in coco with RO water using Jacks at a 321 ratio and at that strength I definitely saw Mag deficiencies. I started using GH CaliMagic and gypsum and the plants are looking better. I upped the jacks to a 3.6-2.4-1.2 ratio and would eventually like to eliminate the CalMag supplement all together and just use Epsom Salts for the Mag and Gypsum for the Cal.
I think anyone would see beneifts from using gypsum even if they dont have any obvious deficiencies. Its a great source of calcium
I used to use this when I ran hydro.
I like to do 3 parts gypsum and 1 part Azomite (sometimes 1/2 part SulPoMag as well) in a jar and soak with apple cider vinegar for a day after shaking well.
It makes for a powerful, soluble CalMag+
Just FYI here.
Diamond K is solution grade gypsum.
If you must use cal/mag try to find one with low or no nitrogen.
Much like lefty already said.
Nice work @lefthandseeds 
Why the CalMag and the calcium sulfate? Just curious.
I use 3.6 : 2.4 (no MgSO4 - but maybe I’ll switch to that and some form of calcium, over the calmag, if I find a good replacement for calcium. I’m growing synthetic.)
I saw that brand somewhere recently.
That sucks about the chloramine. I just recently found out I’d been slightly misinformed, and that our municipality is still using chlorine, and not chloramine (I bet they switch soon, though), so that’s great.
I have potassium metabisulfite, and ascorbic acid to neutralize the chloramines (or chlorine, as I found out). The latter I got for drinking water, the former for plants - but I only just started using the potassium metabisulfite in irrigation water, after a brief test with it a couple years ago.
Yeah I picked it up on Amazon. It smells like vinegar. I don’t use full strength and not every watering like they suggest but as a supplemental preventative. I guess it’s working ok. No negative issues to report anyway.
I’m still up in the air about my water. They’ve switched a couple times due to repair work on the mains. I’ve been letting water sit for at least a day for a few years now. The website says chloramine so now I’m filtering as I’m always trying to help my organic game and don’t want to hurt the life in the soil but I’ll have to say I don’t know that I saw a big impact if it’s been chloramine most of the time. I’ll filter and use this stuff if all seems to continue to go well.
I did consider calcium chloride too, when I was looking into Ca sources. That’s what they use for road salt in places where they salt the roads.
Here what I ended up getting. I haven’t used any yet: REXOLIN Calcium EDTA fertilizer 55 lb.-HECHELCALC
Calcium EDTA chelated 9.7% 1 lb.-Cal-EDTA-1lb.
I just realized the sodium levels now, haha. I can’t get any of the info links (eg: sds, label) to work. I think it’s this, though: https://www.yara.us/contentassets/280676bbae1c466799e9d22b57225584/dissolvine-e-ca-10.pdf/
It can be foliar fed.
Long term I would definitely want to move away from using calmag all together and just get my ratios of dry salts in the proper range to cover the extra calmag needs. I still use the calimagic mostly as a safety blanket because I just started using gypsum and wanted to observe things for a minute before I change up the nutes again. I did back off the strength of the calimagic though from 3ml per gallon down to 1ml per gallon. Eventually once I get more comfortable I will remove the calimagic altogether. I wasn’t too worried about overdoing calcium because high calcium is the new hotness. I actually use all 3 of slownickels dry calcium amendments in addition to the Jacks Part A B and ES. Those 3 are micronized Calcium Carbonate, Calcium Sulfate and Calcium Phosphate.
Calcium acetate and maleate are both water soluble, easily made with vinegar and eggshell or malic respectively if you don’t want to buy them. I tend to use some calcium nitrate for some of the nitrogen needs and it takes care of the calcium as well.
I don’t quite understand how the nutrient companies are using calcium carbonate and for it to be accessible to the plant, as you say, it’s insoluble.
Yeah this is virtually impossible I think, I’ve seen plants grown in near chalk, not happy due to ph granted but the high calcium content doesn’t effect them.
This is from Slownickels IG page in regards to his micronized dry powder Calcium Carbonate product.
“Materials are not soluble. These are micronized rocks and are fed as suspensions.”
How truthful or scientifically accurate that is I cannot say.
Edit: I can say that the micronized products I have of his are extremally fine but whether or not they are fine enough to pass the Calcium Carbonate rock at a small enough micron size directly through the root system or leaf stoma through foliar feeding in a way that the plant can actually use is a very legitimate question. I add to my feed solution, but wonder if it would be better as a foliar feed? He advises either can be done. Again it could just be total BS to try and sell a product lol.
Hmm, idk but it sounds like ‘woo woo’ to me, just because that’s not how the plants take up nutrients… it’s via soluble ions traversing the cell wall using osmotic potential, this needs nutrients to be in solution. I could see a micronised calcium carbonate being faster to be converted to a plant usable form in soil via humic/fluvic acids etc, but anyway you cut it, the cells need soluble ions. Calcium nitrate is by far the cheapest and easiest way imho, doesn’t give you the mag, but epsom salts are cheap.
hahaha nice! Style points awarded sir.
I agree and his explanation sounds sorta suspect. I’ll snap a picture of the label on the package and see if there is any better details provided. there might be some recommendation I didn’t see that says to use it as a soil amendment rather then a direct addition to nutrient feed.
I think the biggest issue with using CalNit is that its directly ties calcium to nitrogen and in most cases people are good with their N levels but want to raise their Calcium levels. So N free calcium sources are becoming popular. I think Athena’s finishing/flush product is calcium chloride with some additional micros
I grow in Coco currently but I am moving back to try soil again.I use Canna’s calmag,lot of N in It,Always gives me excess of N
My tap has too much calcium carbonates and It get the roots unable to uptake other nutrients causing lockouts and all the of issues.Then,I started using Ro with calmag and,even tho I have N toxic a bit,I can grow fine plants
I m also interested in N free calmag
A lot of grow nutrients are too high in nitrates imho. I like to keep things simple so I’ve just use maxi-bloom/lucas formula and add a little calcium nitrate as needed. Never had either a calcium or nitrogen deficiency nor toxicity with this and it’s cheap, easy and reliable.
Yeah EDTA is only good to use in small amounts. That’s why it’s popular choice for micros. But you need a lot more calcium than you can feed with an EDTA.
There’s also this stuff for foliar. I haven’t tested tank mixing for it either. It’s intended for foliar application.
@Andrexl
I use vita link cal mag
Lower n than canna , plus extra iron
: )
I think if we are using 3 part formulas and then having to add calmag on top of it, that is getting ridiculous. At that point, we might as well start mixing our own from the base components. There is no value in having them pre-mixed if they don’t work.
A simple low nitrogen flowering mix is 5 parts (recipe is for 10 gallons nutrient solution at 1.7EC):
Normally, I would also include potassium nitrate and reduce potassium sulfate. But if your only nitrogen source is calcium nitrate, you can see how low the nitrogen is. The problem is addition of other sources – potassium nitrate, ammonium nitrate, magnesium nitrate, MAP, etc.
With this formula, you can increase calcium nitrate and easily exceed 150ppm of calcium and not have toxic levels of nitrogen.
