Hanna Marine Phosphorus Ultra Low Range Checker Reagents (25 Tests) - HI736-25

These are replacement reagents for the Hanna Marine Phosphorus Ultra Low Range Checker (HI736), the handheld unit reef keepers use to measure phosphorus in their tank water. Each pack holds 25 single-use reagent packets, so you can keep testing without replacing the checker itself.

The reagents are pre-measured, so there is no mixing or dosing to get wrong. You add a packet to your water sample and the reaction turns it blue in proportion to the phosphorus present, which the checker then reads. The method is an adaptation of the Ascorbic Acid method from Standard Methods for the Examination of Water and Wastewater, 20th edition. Every packet is printed with its lot number and expiration date, so you can check freshness and trace the batch at a glance.

They suit anyone who already owns the HI736 Phosphorus Ultra Low-Range Checker HC and wants to keep tabs on phosphorus levels in a reef or marine system, especially where nutrient control matters for coral health and algae management. Note that these are refills only and won't work without the checker.

Product code: HI736-25. Package: packets. Quantity: 25 tests.