When to change RO/DI filters?

Salt1972 · Jan 12, 2019

We use a BRS 4 Stage Value Plus RO/DI system.

When do you guys replace your sediment, carbon, and DI resin? Our system measures TDI before and after DI. Our TDS will go to 1ppm and stay there for months - do we replace at 1ppm?

Crabs McJones · Jan 12, 2019

Do you use the color changing resin? I usually wait until the DI is 75 to 80% depleted and then replace it. If your unit has a pressure guage, I replace my pre filters either when the pressure starts to drop, or every 6 months, whichever occurs first.

cracker · Jan 12, 2019

hello salt, I check my tds often . If it's over zero I replace the di resin ( I think one could go a litter higher that's just me) then see how long the new resin lasts. Like Crabs says if the pressure drops & di resin goes quick I'll change all the filters.
I also use 2 carbon cartridges leaving out the sediment. It really helps the ro membrane last a lot longer.

COreef8 · Jan 12, 2019

Like they said I change the sediment filter when the pressure drops. I change the carbon blocks when I start to detect chlorine or chloramine coming out of the wastewater line. DI resin when it turns 80-90% yellow or starts to read 1 tds on the output line. Just make sure if you wait for a TDS reading on the output that you have a second DI canister after the TDS meter probe. I’ll change the RO membrane when my TDS coming out of the membrane starts climbing and RO flushing doesn’t help.

Raxnar · Mar 21, 2019

I was just thinking this the other day! Very similar situation. My tank passed the 1 year mark in January and I've been checking the TDS readings in and out of our Spectrapure 4 stage filter monthly. Here in Victoria we are blessed with really good water. I get a reading of 20 on the input and have never seen anything but a zero on the output. Pressure is fine, albeit its always been a bit low and I've contemplated a booster pump but so far using my 10g reservoir and keeping it topped up has worked out well.

Should the filters be changed yearly, twice a year, more, or less even though output is reading zero?