RODI flushing...

[jasonrusso]

I have never flushed my membrane on my system at home. I do run a DI bypass y every time the system runs and the TDS creep is sent down the drain. I do not think flushing does anything except in a few cases. The membrane is being flushed constantly while running to keep impurities from reaching saturation point and depositing scale on the membrane. One scale is formed on the membrane a city water pressure flush is not going to remove it.

Current membrane is almost two years old I will run it until the rejection drops below 97.5%

Same process for me. However, I don't keep a nice spreadsheet

 

[jasonrusso]

I have a TDS meter before and after the RO membranes and I never really thought to track rejection rate to guage when to change the RO membranes but I will easily track that now!

I have one at the inlet, one after the membrane, and one after the DI. I open the DI bypass and watch the probe after the membrane until the TDS comes down. I use the one after the DI to determine when it's time to change everything out.

 

[Justdrew]

See the 15 minute mark here for discussion on changing RO membrane. Whether this is right or wrong I don’t know but interesting data point:

I like Shane and buy his stuff, but he is the only person I have ever heard in 25 years of owning RO systems to preach that. That idea is not even supported by the vendors that sell the membranes. Check your rejection rate and replace based off that.

 

[afboundguy]

I have one at the inlet, one after the membrane, and one after the DI. I open the DI bypass and watch the probe after the membrane until the TDS comes down. I use the one after the DI to determine when it's time to change everything out.

I have 5 TDS probes (well technically 7 as I have the Hydros TDS probes going in two spots I have HM TDS probes) and this got me to thinking about how I could maybe use another Hydros TDS setup to trigger when the pre-resin/TDS creep flush would turn off