Originally Posted by Alg0rithm
What do you mean by 'Cal Carb in a very pure form?'
Biomin amino chelated Calcium first came to mind..
Any particular brand/product you could recommend?
I use an extremely fine powder form of very pure (I believe it was > 99.9% CaCo3) I bought a shit-ton of a while ago, Ca is 30-35% range. I use 2-3tsp / Gallon, this never clogs any of my spray methods and provides more than an adequate amount of Ca.
IME, the cleaner the Ca product and starting water (RO) the better to ensure proper foliar, this goes for any nutrient(s) you're trying to deliver foliarly...
It's extremely clear within 24 hours when you're getting Ca into your plants correctly. Even if you think things already were near perfect.