Review on Precision Hydroponics Test & Measure Instrumentation for Accurate Aquarium and Substance Analysis by Redfish Rosenhoover

1. requires calibration in all three liquids to get reasonably accurate readings (required when opening new liquids, removing/replacing batteries and in all other cases listed in the instructions on the packaging) 2. Read the reading after 5 seconds ONLY by gently swirling the meter in the sample3. When testing acidic samples, the next reading is likely to be inaccurate even if the meter is flushed. 6.86 Solution MUST be immersed and withdrawn before other samples can be tested. I don't know why this is rated so highly. This meter gave 4-9 PH readings from the same liquid sample (Note: litmus paper can help confirm pH. Some distilled water is labeled as containing minerals that are likely to affect pH.)