To be honest, most Hanna testers are reliable and consistent. The calcium tester is an exception. Results for perhaps the second most important variable in your reef tank will never be consistent. I've watched every video and tried every pro tip, even using lab water instead of RO/DI. Unfortunately Hanna missed one, I would recommend the Seifert test.
Fluval A7551 CO2 Indicator Kit
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FUNSWTM 7 in 1 Aquarium Test Strips: Accurate Water Testing for pH, Nitrite, Nitrate, Chlorine, GH & KH Levels
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49 Review
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68 Review
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