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.
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.
Digital Monitors & Testers
Handheld and continuous digital meters for pH, salinity, temperature, conductivity, and TDS — for spot checks or ongoing monitoring.
Checker Colorimeters
Single-parameter Hanna Checkers for the core reef water tests — alkalinity, calcium, magnesium, nitrate, nitrite, phosphate, phosphorus, pH, ammonia, and copper.
Reagent Refills
Replacement reagents for your Hanna Checkers, sized for 25 tests (100 for the pH HC reagent).
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.