
To my surprise, this dissolved oxygen meter works fairly reliably. I used an oxygen pen to check the oxygen levels in the aquarium and it was very accurate. Thanks to the guide, I learned exactly the steps and methods to calibrate a dissolved oxygen meter. I also contacted the seller with some unclear questions and received a quick response. Very professional seller, very good dissolved oxygen meter.

Digital PH Meter Tester - Tiaoyeer Water Quality Tester With ATC, 0.01PH High Accuracy, 0.00-14.00 Measurement Range, 0.01 Resolution For Drinking Water, Aquarium, Swimming Pools, Hydroponic
8 Review

Efficiently Test Your Antifreeze And Battery Acid With A 3-In-1 Refractometer
18 Review

80 Pieces Water Test Litmus Strips Litmus ph Paper Soil Acidity Meter Liquid pH Tester 1-14
10 Review

π PH 1-14 Extensive Storage Testing Monitoring: Optimize Your Storage with Precise pH Level Monitoring
6 Review

π Unveiling Fluke 107: A Cutting-Edge Handheld Multimeter for Accurate Current Measurements
3 Review

π BIAOLING Accurate Formaldehyde Multifunctional Test: Record, Measure, and Inspect with Confidence
3 Review

π¬οΈ BIAOLING Accurate Formaldehyde Multifunctional Recording: Say Goodbye to Indoor Air Pollutants!
3 Review

Accurate Formaldehyde Multifunctional Detector Recording
3 Review