Hanna Instruments

Hanna Instruments — Digital Water Testing

Hanna Checkers use digital colorimetry to remove the guesswork from water testing. Instead of squinting at a color-matching chart, you get a precise digital readout in a couple of minutes — faster, more accurate, and easier to repeat than liquid test kits. Every item below can be ordered directly through our site and added straight to your cart.

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Test Kits & Bundles

Bundled Hanna Checkers covering a full water parameter panel in one purchase, for reefers who’d rather not build a testing lineup one checker at a time.

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Digital Monitors & Testers

Handheld and continuous digital meters for pH, salinity, temperature, conductivity, and TDS — for spot checks or ongoing monitoring.

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Checker Colorimeters

Single-parameter Hanna Checkers for the core reef water tests — alkalinity, calcium, magnesium, nitrate, nitrite, phosphate, phosphorus, pH, ammonia, and copper.

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Reagent Refills

Replacement reagents for your Hanna Checkers, sized for 25 tests (100 for the pH HC reagent).

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Don’t see what you’re after, or have questions about which Hanna Checker fits your setup? Email us at jamie@theunderwatergardener.com and we can help you pick the right one.