Use these to calibrate one of the cheap yellow PH pens shown here. I used to buy a new Ph Pen every growth streak, but now I can just calibrate it and save money in the long run.
๐ PH 1-14 Extensive Storage Testing Monitoring: Optimize Your Storage with Precise pH Level Monitoring
6 Review
TDS water quality tester - TDS water hardness meter (portable digital salt meter for water analysis)
9 Review
80 Pieces Water Test Litmus Strips Litmus ph Paper Soil Acidity Meter Liquid pH Tester 1-14
10 Review
Efficiently Test Your Antifreeze And Battery Acid With A 3-In-1 Refractometer
18 Review
๐ฌ๏ธ Advanced 3-in-1 Indoor Air Quality Monitor with CO2/RH/Temp Data Logging and Audible Alarm - NDIR Sensor Technology
8 Review
๐ฅ Advanced Testo Wireless Hot Wire Anemometer Technology
4 Review
๐ก๏ธ Continuous Temperature Monitoring with Relative Humidity Integration
4 Review
๐ง UEi Test Instruments DAFM3B Digital Multimeter
6 Review