I’ve always used a cal mag supplement of some kind, and I usually ad epsom salt too. I was thinking, could I make a liquid solution of epsom, and one of gypsum, then use them as my calmag? Or to supplement? I’m trying to break my bottle additive addiction. I started out that way using fox farms way back when, and even though I’m in wonderfully amended organic soil, I still reach for my roots organic bottled nutes and mr muchastache calmag.
For my main nutes I’m going to try using just the roots terp teas this run, SST’S, and cal mag. But I want to stop using liquid calmag if possible on my soil and use what I have for my hydro experiment. I have some liquid guano and fish emulsion I’ll probably add during flower, just to use up.
I have done the vinegar eggshell technique and used it with some success.
I didn’t ever see any deficiencies BUT I ended up going back to a traditional bottled calmag because I could never be certain of the dose and I didn’t like that.
So im thinking I can do the chemistry to use a slight mod of that tek. Let me write it up and think about it, and I’ll post back.
In theory I could use gypsum as my Ca source, and it would just release Sulphur oxide/dioxide yielding Ca acetate, then add dissolved mgso4 as my mag source, ph it with KOH which should make some MgOH and KSO4 too, then just use molasses for Iron, trace minerals and as a carb source? Let me burble my brain now that I have a framework.
So, im going to base it off my vinegar solution, if its approx 5%, then I have 5 ml in 100, I already rinsed some of my gypsum, leaving a gray powder, now I soak it in white distilled vinegar until it stops bubbling (holy crap does it smell like sulphur btw).
So basically… molarity of pure acetic acid is 17.416 (I’m assuming 5% concentration), molarity of caso4 is 136.14. So for 1g clean and dry caso4 I’ll need about 156 times the weight of vinegar, about 160 ml, to have a slight excess. This will give me 1g in solution per 160ish ml, with minimal mag, n, p, or anything else. Acetic acid breaks down into water and co2.
So, I’m thinking the gypsum dissolved into vinegar might work well as a foliar, but far too dilute to use as a cal mag supplement. I mean you need 16x to equal cal % as calmag. Now if you used a higher concentration vinegar… then were making something usable.
Now to read more in depth on that page and modify my idea.
I have crystalline citric acid on hand, I could turn the gypsum into calcium citrate, or rather calcium sulphate chelated with citric acid. Looks like thats a good foliar spray. How would a citrate salt work in soil though?
Iron reacts with citric acid , yielding ferrous citrate FeC6H6O7. … While the magnet is holding the residual metallic iron , you can pour out the colorless ferrous citrate solution. Hydrogen peroxide H2O2 oxidizes iron (II) to iron (III), forming a yellow ferric citrate FeC6H5O7 solution.