HP2 and HPK are Roots Organics’ two liquid guano boosters. HP2 is pure phosphorus from liquid seabird guano, while HPK is phosphorus from seabird guano supplemented with potassium from the mineral langbeinite. Roots Organics separated the two products because coco, which is often present in quality potting soils, has a high cation exchange rate with potassium. It is not a good idea to add too much potassium in a coco heavy medium, hence offering pure HPK as a separate option.
Derived from 100% natural seabird guano and biogenic phosphate rock.
Soil or Hydroponics
Add 1 TBS (15 ml) per gallon. Use during fruiting or flowering.