Hanna Total Chlorine ULR Reagents – HI-761-25

Hanna Total Chlorine ULR Reagents – HI-761-25

Hanna Total Chlorine ULR Reagents – HI-761-25 is a replacement Hanna reagent product for compatible total chlorine testing equipment. Use it with the correct Hanna meter, checker or analyser to keep routine testing accurate.

Hanna Total Chlorine ULR Reagents – HI-761-25 is the matching Hanna reagent refill for use with the compatible Hanna tester. It is intended for customers who already own the meter or Checker and need replacement reagents to continue testing accurately.

Using the correct Hanna reagent is important because each checker and photometer is programmed around a specific test method, wavelength and reaction time. Substituting a different reagent can give unreliable results or make the test unusable.

Keep a spare reagent pack available if you test regularly, because water quality issues often need confirming quickly. This is particularly useful after new fish, pool dosing, algae treatment, filter maintenance or water changes.

Where this product fits in your testing routine

Chlorine testing is important wherever tap water, treated water, pools or dechlorination are involved. Digital testing helps confirm whether chlorine is present rather than relying on colour matching by eye.

Use the result alongside what you can see in the system. Fish behaviour, coral response, pool clarity, chlorine demand, algae growth and recent maintenance all give context to the reading. If a result seems surprising, repeat the test with clean equipment and fresh consumables before making a major change.

For ponds and aquariums, testing is especially important after heavy feeding, new livestock, filter cleaning, algae treatments, medication, large water changes or hot weather. For pools and spas, a consistent test routine helps maintain safe water and prevents chemical adjustments being made blindly.

Using Hanna equipment correctly

Most Hanna digital tests rely on good technique as well as good equipment. Use clean sample containers, avoid fingerprints on optical cuvettes, check that reagents are within date and follow the method timing carefully. Small errors in preparation can make a good instrument appear inconsistent.

Store consumables sealed, dry and away from heat or contamination. Do not use damaged sachets, dirty bottles or expired standards for important decisions. Where a result matters, good consumables are just as important as the meter itself.

Key benefits

• Correct Hanna consumable for the matching tester
• Helps maintain consistent test method and result quality
• Useful refill pack for regular testing routines
• Avoids running out of reagents when a water issue needs checking
• Best stored sealed, dry and within the expiry date shown on the pack

Technical details

• Product code: HI-761-25
• Brand: Hanna Instruments
• Measurement Range: 0 to 500 ppb (total chlorine)
• Method: DPD method
• Test Quantity: 25 tests
• Result Units: ppb (µg/L)

Compatible consumables and useful extras

For this product, the most relevant extras are Hanna Total Chlorine Ultra Low Range Checker HC – HI761, Hanna Ultra Low Range Chlorine Calibration Check Standard Set (0 & 200 ppb) for HI761 Checker – HI761-11, Hanna Spare Glass Cuvettes with Caps (2 Pack) – HI-731315. These are the products most likely to be needed for regular testing, verification or maintenance, so they have been prioritised in the recommended extras where available.

Choosing the right add-ons is not about buying more for the sake of it. It is about making sure the tester can actually be used when needed, especially if you rely on it for fish health, reef stability, pool safety or professional maintenance.

Storage and replacement advice

Consumables are a small part of the testing kit, but they have a big influence on the result. Store them carefully, keep caps and sachets clean, check expiry dates and replace anything that has been contaminated or left open. This is especially important for pond, pool and aquarium keepers who make dosing decisions from the readings.

If you test regularly, it is sensible to keep the matching tester, refill reagent, standards and cleaning products together. This keeps the routine simple and makes it much easier to confirm a result before treating the water.

Helpful Hanna links and compatible products

Use these links to compare similar Hanna products, find the correct consumables and build a more complete water testing routine around this item.

• Browse all Hanna Instruments products
• Browse water testing and purifiers
• View related Hanna chlorine products
• Browse Hanna pool testing products
• Hanna Total Chlorine Ultra Low Range Checker HC – HI761
• Hanna Ultra Low Range Chlorine Calibration Check Standard Set (0 & 200 ppb) for HI761 Checker – HI761-11
• Hanna Spare Glass Cuvettes with Caps (2 Pack) – HI-731315

Advice from That Pond Guy

We recommend keeping water testing simple, consistent and repeatable. Test at similar times where possible, keep notes of important readings and look for trends rather than reacting to one unexpected result in isolation.

If you are using this product on a pond, aquarium, pool or holding system, think about the whole setup. Filtration, aeration, stocking, feeding, chemical dosing and source water can all affect the numbers. A reliable Hanna reading gives you better information, but it still needs to be interpreted in the context of the system.

Helpful water testing guides

For more background on testing, interpreting results and maintaining stable koi pond water, see these related guides:

• guide to maintaining ideal pond water conditions
• koi water quality guide