Could you explain more whether it is the calcium or is it the magnesium that cures the yellow die back of leaf tip?Hey Eric, I would say it wouldn't be a bad idea once in a while to boost with calcium nitrate, but not absolutely necessary with MSU. Epsom salts, yes, absolutely add more magnesium periodically, especially for roths and any Paph you start to see that brown leaf tip die back with a yellow leading edge, the stuff you cut off and it starts right back up regardless of what you treat it with.
I get mine at my local garden center. It came in what looked like a milk carton. I'm almost out and need to buy more. The drugstore stuff should be the exact same thing, but make sure there aren't any additives like perfumes or color as some manfacturers specifically make a product for baths and foot soaks.I think I'm sold on this whole Epsom salts deal. Where should I pick some up? Is there any chance the drugstore stuff is ok?