Keep trace phosphorus checks ready for your marine system
Track low-level phosphorus in saltwater without preparing bulk reagent. HI736-25 supplies matched, premeasured powder reagent for 25 tests with the HI736 Checker or the explicitly supported marine ULR benchtop methods.
Manufacturer stock illustration. Pictured packet lot and expiry are historical and do not describe the stock supplied.
Choose the refill that matches your method
Choose this refill when you want to follow small phosphorus changes in a marine system and already have a supported reader. Adding a matched packet to each sample keeps reagent preparation simple and helps preserve a repeatable testing routine.
Know what your result represents
Benchtop menus call this Phosphate, Marine Ultra Low Range, but the base result is reported as phosphorus (P). A result of 200 ppb P is not 200 ppb phosphate (PO4). Use the instrument’s chemical-form conversion when a phosphate-basis result is needed.
What is included — and what to have ready
Reagent for 25 nominal tests. Each measurement uses one HI736-0 packet. The meter, sample cuvettes, caps and check standards are separate.
Have a compatible meter, clean model-appropriate cuvette and cap, and the sample-handling accessories specified by that instrument. A lint-free cuvette cloth and cuvette cleaning solution are useful separate maintenance supplies; a model-specific check standard is optional and does not replace the analytical reagent. The stated capacity is 25 tests, not a bottle-volume or powder-mass specification.
Use the procedure for your instrument
The exact reagent set is listed for HI736 and for the marine method on HI83300, HI83303 and HI83399. Select the documented method, follow its blanking, addition and reaction steps, and keep cuvette exteriors clean. Do not transfer Checker timing or optical specifications to a benchtop instrument.
Handling and documentation
Read the HI736-0 component Safety Data Sheet and the selected instrument method before use. Follow the instructions on the actual reagent supplied.
Hanna classifies this exact refill as Dangerous Goods and states that it can only be shipped via ground.
Frequently asked questions
When should I choose HI736-25?
Choose this refill when you want to follow small phosphorus changes in a marine system and already have a supported reader. Adding a matched packet to each sample keeps reagent preparation simple and helps preserve a repeatable testing routine.
Which instruments are supported?
Use HI736 Checker or the explicitly documented marine method on HI83300, HI83303 or HI83399. The compatible-instrument cards below link existing benchtop pages; no general compatibility with all photometers is implied.
Is this a phosphate reading?
The base range is 0–200 as phosphorus: ppb P on HI736 and µg/L P on the listed benchtops. Their Phosphate, Marine Ultra Low Range method name does not make the same number a PO4 result. Select the appropriate chemical-form conversion rather than relabeling the reading.
How many tests does one pack provide?
The nominal capacity is 25 tests using the specified method. This is a test-capacity statement, not a total reagent fill volume or powder weight. Repeat measurements consume reagent too.
What comes with the refill, and what is separate?
Reagent for 25 nominal tests. Each measurement uses one HI736-0 packet. The meter, sample cuvettes, caps and check standards are separate.
Can I use the Checker instructions on a benchtop?
Use the current procedure for the exact reader and selected method. Sample handling, blanking and reaction timing must follow that manual; shared reagent identity is not proof that every instrument setting is identical.
What accessories help routine testing?
Use clean cuvettes and caps specified for your instrument. A lint-free cloth and cuvette cleaning solution help maintain clear optical surfaces. Model-specific check standards are optional and are not reagent replacements; Checker cuvettes should not be assumed to fit a benchtop.
Where are the safety instructions, and does the photo show my lot?
The Manuals/Brochures tab links the verified HI736-0 US component SDS and instrument method PDFs. Check the labels on the pack you receive; the manufacturer illustration does not establish the supplied lot, expiry or remaining shelf life. Hanna lists this refill as ground-shipping-only Dangerous Goods.
