Add 750 ml RO water to a 1L jug. Add 150g calcium chloride, 1 gram boric acid (borax). Close the bottle and shake. Top up to 1L with RO water.
Use at 5ml/4L (~1 gallon) foliar as a replacement for Ca-25.
I can't help you with the plant wax. It could be some kind of emulsifier like xanthan/guar gum.
Have you tried this yourself? Been looking for a replacement to the ca25. Really shocked me when they went out of business.
Calcium-25 was recommended at 4oz/400gal, or ~4.5g/gal, which is a much higher dose. Tria is typically used at <1ppm, after dissolving in polysorbate 20, but you can always skip the science and substitute CannaBoost or something similar. So, one liter of RO, one gram of calcium chloride, plus your tria, and a surfactant is a good, ready to spray approximation. I don't really imagine that 10mg of borax is going to be sufficient as a surfactant, but that's inline with Bill's recipe, and probably the answer to the question which started this thread.
No, I have not tried the above. I'm currently foliar feeding
Fasilitor, which covers boron, as well as adding silica;
Massboost, which covers calcium, as well as adding magnesium and aminos; and Cannaboost, which covers tria, as well as adding 6BAP, a bunch of micros, including boron, and some anti-fungal properties which contribute to IPM.
I still have a few ounces of Calcium 25, but I like this better; who knows though, perhaps I'll get it analyzed or something.