Replacing DI/Carbon/Prefilter

[Webbed Feet]

Hi,

In your RO/DI unit do you typically replace all three canister DI/Carbon/Prefilter when ever the DI gets tired or do you do something different such as replace the Carbon/Prefilter every other change of DI?

[Blue Z Reef]

This is why I always recommend the triple TDS meter. You can test incoming TDS, post membrane, and post DI. For me, knowing this allows me to know when my carbon blocks are nearing end of life, which is separate from when DI starts exhausting. Typically, carbon blocks are good for 6 months, primarily due to how long the carbon is still active for. A pre filter is going to depend on your personal water source. I’ve seen tons of people online with pre filters turning nasty brown. I’ve honestly never had once change different than white. As long as pressure isn’t dropping, I’d probably give it a quick rinse but likely wouldn’t replace it on the same interval as say a carbon block. Again though, that is my water, your may be different. Camas TDS runs about 60 from the tap for me. In Vancouver at my last house, I was at 120. Some spots in Portland are only 5! All depends.
 

So all that said, I’d consider the HM triple TDS meter to get a better understanding of where you sit at each stage so you can make a more informed decision on swapping filters/DI.

[obrien.david.j]

I'm in the low teen's in the winter/spring.  and the low 20's in the summer/fall.

From April:

 

[pdxmonkeyboy]

first we need to know what your water source is...  

 

[Oregonic]

I have had good luck swapping sediment filter when it starts to look fairly yellow, roughly every 200ish gallons of usable water. Sediment filters are cheap. Every two times I swap my sediment I also swap my carbon. Every 2 times I swap my carbon I swap my resin. Thats what has worked for me on East side Portland water. Once producing water for about 1 minute I usually have about 3-7 tds prior to resin and 0 after the resin using this method. I dont use any water till I read 0 after the resin. 

[bamburgb]

On 10/26/2020 at 10:12 AM, obrien.david.j said:

I'm in the low teen's in the winter/spring.  and the low 20's in the summer/fall.

From April:

 

dang i live in Scappoose and during the summer months mine reads approximately 110 coming in (always 0 out after my DI).

[Webbed Feet]

I am in Tualatin on city water.  Sounds like adding a meter prior to all filters and one in-between the membrane and DI (already have one after DI) might be a good idea.