HI736-25 Hanna Phosphorus Reagents — 25 Tests for Checker HC HI736 - Hanna

Hanna HI736-25 phosphorus reagents — 25 tests for the Hanna Checker HC HI736

The Hanna HI736-25 reagents are the dedicated reagents for the Checker HC HI736, a Hanna Instruments pocket colorimeter that measures phosphorus in reef marine aquariums. Each box holds 25 individual tests, one per measurement. The formula is calibrated to the LED and the chemistry of the Checker HC HI736 — using a reagent from a different model gives wrong and meaningless readings.

In practical use, this reagent pack lets you ULNS SPS reef tanks where PO4 sits below 0.03 ppm — ppb-level precision.

What these reagents bring

• Ascorbic acid method (reactive phosphorus) — the same chemistry used in the lab and calibrated to the Checker HC HI736 LED.
• 25 tests per box — enough for 2 to 6 months of monitoring depending on frequency.
• Genuine Hanna formulation, made in the same conditions used at the factory to calibrate the colorimeter.
• Pre-measured sachets — no scale or pipette needed.
• Reproducible readings when procedure is followed (rinsing, timing, agitation).

Measurement procedure

• Rinse the cuvette with RO water, then with sample water.
• Fill to the mark, insert the cuvette and press Zero.
• Add the contents of one HI736-25 sachet and agitate for the time specified in the Hanna datasheet.
• Reinsert the cuvette and press Read — the reading appears on the digital display.
• Rinse the cuvette immediately with distilled water to prevent residue.

Specifications

• Hanna reference: HI736-25
• Number of tests: 25
• Compatible with: for the Hanna Checker HC HI736
• Parameter measured: phosphorus
• Range: 0 to 200 ppb
• Method: Ascorbic Acid method (reactive phosphorus)
• Storage: dry, room temperature, out of direct sunlight.

Why get these reagents from ReefSolution

• Hanna Checker HC HI736 — the matched colorimeter for these reagents; always use fresh reagents to preserve instrument accuracy.
• Hanna Checker HC HI772 dKH alkalinity — the reef parameter that shifts fastest; measure twice a week on an SPS tank.
• Hanna Checker HC HI758 marine calcium — completes the reef Ca/KH/Mg trinity.
• Hanna Checker HC HI783 marine magnesium — measure every 2-4 weeks.
• Hanna HI98319 waterproof salinity tester — salinity in ppt/PSU/SG with temperature compensation.

Frequently asked questions

How many tests are in a box of Hanna HI736-25 reagents?

25 individual tests — one reading per Hanna Checker HC HI736 measurement. That typically covers 2 to 6 months of tank monitoring.

Can I use Hanna HI736-25 reagents with a different Checker model?

No. Each reagent reference is calibrated to the LED and chemistry of its matched Checker HC. Using another model's reagent produces wrong readings.

How should Hanna reagents be stored to preserve accuracy?

Store dry, at room temperature, out of direct sunlight. Do not open the sachets in advance — the chemistry degrades on contact with humidity.