wes84
2500 Club Member
I think my tap water has high chloramines. Right now im going tap straight to the rodi unit but i have a whole house filtration and softener (true softener with brine tank, not a conditioner) to install when i find time (and figure out where the dang water supply runs, ive already cut 3 holes in my ceiling chasing it from the garage where i have no sewer connection for the backwash but i think it runs up into the attic of the 2nd story). Last time i changed out the resins the second canister (i think anion) was getting full but the first hadnt changed color hardly at all.That little use a month for a 7 stage, you're barely using it.
But it depends on you tap water, sediment, TDS, and if you have chloramine.
Your sediment filters and carbon should last a year unless you have high sediment in your tap, or chloramine.
You're RO membranes 1-2 years. Again it depends.
Your resin, well again it depends, I assume it's color changing. But as @CodyBot has mentioned the change of color isn't always accurate.
I would suggest a TDS meter before the resin and post resin at a minimum.
Preferably one between each resin container. It might help telling when one resin is exhausted . If you want to monitor the RO, one before it too.
Unless you have high silicate in you water, splitting the resin isn't really worth it. They both run out about the same time. 3 mixed stages would be just as well, when the first one runs out you can swap it. Nothing will make it past the second and the 3rd is just a safety.
Now the question is, do you want to squeeze every last drop out of the filtration or play it safe.
Playing it safe, change the sediment and carbon every 6 months, RO every 6-12 months. Again it depends on your source.
Carbon can get clogged with bacteria, especially in a system that is barely used.
KDF can actually be useful in this to prevent bacterial growth, removing heavy metals and chlorine. Placing it before the carbon. But KDF requires backwashing occasionally as like GFO it's heavy and clumps. They also have now KDF sponges which don't require frequent backwashing.
Catch is KDF has copper and zinc, but unless you have reactive tap water, there isn't a concern. KDF can actually trap free copper ions, as well as lead, chlorine, mercury, chromium, and many other metals. Also preventing bacteria and slime buildup in your filtration system.
Plus you have RO membranes which remove those and Resin to further scrub the water. The main benefit of KDF will be removing some of those heavy metals and preventing the bacteria and slime buildup before it gets the carbon and RO membrane.
Again the reason it is not used in our system is KDF requires back washing It's also pretty expensive compared to carbon. And our RO membrane take care of those metals anyway.
But bacteria and slime inhibiting qualities would allow our carbon to work better.
Sorry for the long rant.I learned a lot researching and installing my whole house filtration last year.
