| Component | Concentration (w/w) |
| Potassium (K2O) | 21% |
| Phosphorus (P2O5) | 20% |
Mr. K Max 21 is a potassium phosphite that contains activated high energy phosphorus in the form of phosphite. Phosphite has one oxygen molecule lower than phosphate in its chemical structure that makes it more active and gives anti-fungal effects to the product. So, Mr. K Max 21 is a dual-purpose product which meets the requirements of the plant to phosphorus and potassium on one hand, and on the other hand increases the resistance of plants against diseases. This water-soluble fertilizer has great effects on plants flowering and fruit set, when applied during the early growth stages.