carefully remove the filter

Each filter has a verified* filtration capacity of 200 gallons

Oxidation changes both the distance and surface

Make Every Plant Your Best Plant

Air tight bottle with a tamper-proof seal

Ten (10) Pack Hanna Calibration Check Solution for HI9813-6 no electricity water pump carefully remove the filterHI50021 is a premium quality calibration check solution used exclusively for the HI9813 6 portable pH EC TDS Temp. meter. Each sachet has the lot number and expiration date stamped on it and is made of light block foil ensuring freshness each time one is opened. Hanna's line of solutions have been specially formulated to have an expiration of 5 years from the date of manufacture for an unopened sachet. The HI50021 is for 10 sachets containing 20 mL of