Potassium Nitrate is the backbone of the PPS-Pro macro bottle. It’s the primary source of nitrogen in the system — the nutrient that plants consume in the largest quantities and the one most likely to run out first.

Nitrogen drives everything you can see above the substrate. Leaf growth, stem strength, the deep green colour of healthy plants — all of it depends on a consistent nitrogen supply. When nitrogen runs low, plants go pale and growth slows noticeably. It’s usually the first deficiency you’ll spot, and the easiest to fix.

In PPS-Pro the macro bottle is mixed using 250g of Potassium Nitrate, which is exactly what this pack contains. When your macro bottle runs low, this is likely the first compound you’ll need to replace. Buy it individually and top up without having to replace the whole kit.