Neptune Systems PM1 Probe Module - pH, ORP, & Temperature Brand_Finnex It then passes through the

It then passes through the mechanical filtration stage

Fluval 305 External Power Canister Filter (A211)

It reduces the possibility of nitrite poisoning

Glass Canopy - 48 x 18

Neptune Systems PM1 Probe Module - pH, ORP, & Temperature Brand_Finnex It then passes through theThe PM1 probe module is just what you need if you want to monitor pH or ORP in your tank. And, there is an added bonus, you get an extra temperature port as well as six I O switch inputs for use on ATO, feed buttons, or whatever else you may come up with. This module is perfect for someone that wants to add an additional pH or ORP port to their Apex System. Monitor Control pH or ORP, and temperature 6 digital inputs for float switches, water on floor