Oakton (WD-35801-02) pH Electrode SGL JCTN INL-SUBM 400 GPD @ 4" X 40" Hanna's EDTA titration method is

Hanna's EDTA titration method is recognized for accuracy in determining total hardness expressed as CaCO₃ equivalents

or when calibration no longer holds

maintain flow rates at or below 3 GPM during peak demand periods

5" diameter filter cartridge

buoyant housing

Oakton (WD-35801-02) pH Electrode SGL JCTN INL-SUBM 400 GPD @ 4" X 40" Hanna's EDTA titration method isOakton Professional Grade pH Electrode SGL JCTN INL SUBM Single junction, inline submersible pH electrode designed for continuous monitoring in demanding aquatic environments Model WD 35801 02 Submersible Design Oakton Compatible WHY IT WORKS Built for Submersion and Continuous Use Inline Submersible Designed to remain submerged for extended periods, ideal for monitoring tanks, aquariums, and process water applications Single Junction Design Reliable