but it does light up and gives an accurate reading

Residential users should use tap water (inlet) and post membrane (pure) as outlet

Instructions : COMPACT III INSTALLATION INSTRUCTIONS

OR if you want to change di resin a lot less frequently

Our RO systems come to you fully assembled and are 100% plug and play

Filter Monitor with Volumizer BoosterPump but it does light upFilter Monitor with Volumizer The Filter Monitor is an innovative system to alert when a filter needs to be changed via color coded lights at the base of the faucet. The battery powered FM 2 has five timers for a 5 stage system, as well as a water volumizer and programmable set points and alarms for each function, all in a crisp, attractive housing. This is a great product to help you keep track of your filters in ANY RO unit.