sir_isO

@Shotiie, Well, for sulfur I would usually say epsom salts but I dunno coz of the magnesium in your case so that's a bit tricky. Boron just very small amounts of borax. Good soft rock phosphate would be my recommendation for phosphorus in general, but also, that's slow release stuff so in your case (single) super phosphorus. It usually has good calcium and sulphur levels too so you can just add a bit of epsom salts with that (for a good calcium and magnesium balance, phosphorus and sulphur) along with the boron. Another thing I'd kinda recommend in general (more for younger plants/soil though) would be kelp, it's quite effective. https://en.wikipedia.org/wiki/Ecklonia_maxima but I dunno about availability or price of this shit in your area. Like, I only tentatively recommend that, coz judging by pictures can be tricky and I have no idea what nutrients and stuff you're using. I tend to use the cheapest shit I can. Good luck though. Just in case you think I'm fucking around (which I do, often, like I sometimes make terp juices from flowers and leaves, mulberry yoghurt shit for the plants, random crap like that) or don't know my shit (and I kinda don't)...this was early last year: https://ibb.co/5hvw8Pn