PK that is organic

And yes super phos rock works really well, imo. Though I use "light" supers. like 14% phosphorus. but it works good, fairly quick release. You can just sit it in water, add citric acid maybe a bit of soil/microbe stuff along with molasses, sugar or something to kinda "prep" it. Like one day, and it's good. Usually has good calcium and sulphur with it.

Soft rock phosphate and potash.

B.A.C. make an organic P/K booster. It is a single bottle formula and very concentrated, meaning you don't have to use much and a bottle will last many, many plants or multiple grows. And the best thing - it actually works! Bio Diesel by Sensi is another product, which is guano based and works very well, but half strength is plenty strong enough. Bio Canna make Bio Flores, that is a complete bloom fertilizer with elevated P and K levels, which works well too. Any other "raw" sources of P and K are very slow acting and for best results can be mixed with your soil a cycle before it is needed, that is, make the P/K mix in advance (10-12weeks) before you need it, so that the the soil microbes can break it down into a state whereby your plants can use it straight away. Hope this helps,............. Organoman.

Hi mate, you could ferment some banana skins in sugar water for a couple of weeks. That is a good PK boost for you plants. Good luck and happy growing

BioBizz seem very popular, I'm trying them for my next grow.

Cellmax Bio Bloom : https://www.cellmax.eu/shop/cellmax-organic-bloom/