RO/DI question

[tjm80]

My RO/DI system is reading 3 tds and I was reading about how to know which filters need replaced, and read somewhere to test the water after the RO membrane, but before the DI resin. I'm showing 7 TDS after the RO, and 3 after RO/DI.

Should I replace all filters, or any one(s) in particular? Is 3 TDS acceptable? I know 0 is the goal, but can those 3 little parts per million really make that much difference?

I'm ashamed to admit this, but the system is a year old and I've never changed the filters...

 

[ccCapt]

What is the TDS of the water before it goes into the filter? You want the water to be around 95% "cleaner" after the RO than it was coming in.

 

[bskerrichard27]

Mine reads 96 befor ro/Di and zero after if u are getting any tds after it runs through u need new filters

 

[tjm80]

What is the TDS of the water before it goes into the filter? You want the water to be around 95% "cleaner" after the RO than it was coming in.

150-160, which is around that 95%. I ordered a second DI cartridge last night and will buy some resin from the LFS to change out the resin in the cartridge I already have. Do you think this would bring me down to 0?

 

[bskerrichard27]

Well I know the one I got from bulk reef. Brings me to 0 and from what I read if its not at 0 u need new filters

 

[Mpfaff77]

If you havnt changed filters in year change them. Should change RO filters every 6 months. The DI you should change when you get tds reading of 1ppm out of DI. So change all filters. Membrane still good after year

As far as RO reading it may not take it down to 0ppm which is ok. My water from tap had low tds at 53ppm. So my RO is also 0ppm. But tap can be high tds and you may have a reading. I run off water before I run into DI. I have a few valves to divert it to drain line because you can get tds spike when first start up system. By running it for few it will lengthen life of DI canister. I am about 15 months and still reading 0ppm. When i run off for few minutes. Sometimes I get spike to 35 ppm then will slowly go back. I then re route back up DI when hits 5ppm. Then start making fresh water for tank.

 

[Mpfaff77]

150-160, which is around that 95%. I ordered a second DI cartridge last night and will buy some resin from the LFS to change out the resin in the cartridge I already have. Do you think this would bring me down to 0?

No need to have 2 DI canisters. Just change 3 stages of RO and get new DI resin. You should get your 0ppm

 

[tjm80]

No need to have 2 DI canisters. Just change 3 stages of RO and get new DI resin. You should get your 0ppm

The first pre filter and both carbon blocks, right?

 

[Mpfaff77]

The first pre filter and both carbon blocks, right?

Yes. Pre filter. 2 carbon blocks and new DI resin.