Hanna HI981 Checker Phosphate

The Hanna HI981 Checker is a pocket-sized digital colorimeter that measures phosphate (as PO4) in the low range of 0.00 to 2.50 ppm, designed for freshwater planted tanks and low-nutrient reef aquariums. Unlike liquid test kits that rely on subjective color matching, the HI981 uses a photometric sensor to deliver a numerical readout with a resolution of 0.01 ppm, virtually eliminating user reading error. The device operates on a simple two-step process: measure a blank sample, add the reagent, and read the result in under 3 minutes. Replacement reagent cuvettes are available separately. This level of precision is invaluable for managing algae in planted tanks and for reef keepers targeting ultra-low phosphate.