How long will deionization resin last?

[Cory]

My tap water tds reads 150-200, after ro membrane it reads .001, and then after the di it reads .000. How long will my di last?

 

[phillrodrigo]

There are many factors but mine is close to that. My spectrapure last about a year

 

[cdness]

My resin lasts around a month... High CO2 content in the water kills my resin.

 

[Randy Holmes-Farley]

You sure you read 1 ppm TDS after the RO when you have 150-200 ppm before it?

If so, that is a very effective membrane.

At 1 ppm TDS, the DI should be able to produce quite a lot of water. My post RO water hits the first of two DI cartridges at about 9 ppm TDS, and I get a few hundred gallons from it. Ideally, you'd get maybe 9x as much, although I doubt that the 1 ppm TDS is real. :)

 

[Cory]

I just use a Home Depot watts brand. I bought the Deion separately. After the first 6 months I changed the micron filter, but was surprised to see it was still white with a tiny bit of brown! Where in my home town Winnipeg, it was black after that time.

Randy it's possible at the time I read it it was 90ish tds down to .001. are those more common numbers? I can double check later on. Apparently here in GP we praise are awesome tap water haha.

 

[Randy Holmes-Farley]

I just use a Home Depot watts brand. I bought the Deion separately. After the first 6 months I changed the micron filter, but was surprised to see it was still white with a tiny bit of brown! Where in my home town Winnipeg, it was black after that time.

Randy it's possible at the time I read it it was 90ish tds down to .001. are those more common numbers? I can double check later on. Apparently here in GP we praise are awesome tap water haha.

99% rejection is possible. Mine is much poorer at about 90%, but I still get plenty of mileage from my DI. The exact % rejection will depend no only on the membrane but on what is in the water. Some things get through fairly readily. CO2, for example, as someone noted above, gets through very easily. So does anything small and not charged, such as ammonia, silicic acid, boric acid, arsenic, etc.

 

[Cory]

Thanks for the move, it's not often you get moved for free! Haha

I was surprised to see it so low myself, I thought "this thing works really really good, maybe I don't even need a di". But I got one anyway. If it's at 99% I bet Te city water is great. Well thanks for the help!

 

[Randy Holmes-Farley]

The good think about TDS so low that you think you might not need it is that the DI will hardly cost anything because it will last so long. ;)

 

[Cory]

If it really is .001 tds then how many gallons of filtered water am I looking at before I should start to worry?

 

[Cory]

Oh and I checked the meter it reads 76ppm tds in and .001 out, 0.after te di. But maybe I put the meter to read after it filters it. I'll have to double check that.

 

[Randy Holmes-Farley]

The exact amount DI water you get before depletion will depend the DI resin type as well as the TDS and the nature of the chemicals in the post RO water.

Spectrapure suggests that at 20 ppm TDS, you'll be able to treat about 400 gallons with their high capacity DI, which they claim is about 3.5 times as much as a normal cartridge. So that means about 100 gallons for a normal cartridge at 20 ppm TDS input. At 1 ppm TDS input, you'd get much more, probably something like 10X more. :)

 

[fungia_fiend]

Those longevity estimates seem low to me, Randy. I come out of the RO with about 8ppm, and the DI lasts 400-500 gallons for me before noticing a TDS rise out of the DI. My DI is not a high capacity, just run of the mill self fill DI. Maybe I'm just lucky with what's in my water?

 

[cdness]

some of the ions the DI resin removes is not detectable with a TDS meter. CO2 is one of them, but ammonia is another. If you have some of these in your water after the RO membrane, the DI will deplete faster. It all depends on the contents of the incoming water. This would be easier to describe by comparing two different water quality reports. Check out your local report and see what is really in the water.

 

[Randy Holmes-Farley]

Those longevity estimates seem low to me, Randy. I come out of the RO with about 8ppm, and the DI lasts 400-500 gallons for me before noticing a TDS rise out of the DI. My DI is not a high capacity, just run of the mill self fill DI. Maybe I'm just lucky with what's in my water?

I'm not sure what chemicals in the water Spectrapure based that on, or even what "standard" DI resin they are comparing to, so it's hard to say why you get more, but if you do a lot better, be happy. :D

FWIW, I'm also not sure how accurate the inexpensive inline meters are. It doesn't matter for most purposes, but for a calculation like this it might throw off the expected lifespan of the DI resin.

A different reseller, AIr Water Ice, used to claim that you could calculate the lifetime of a DI as:

6800 divided by the ppm TDS = gallons

So at 20 ppm TDS, that's 340 gallons. :)

At 1 ppm TDS, that's a whopping 6,800 gallons.

 

[Cory]

Bumping up an old thread. But a good one.

So ive got city supplied well water now, and im wondering if my deion resin will last as long. Tap tds is typically 600-950ppm. Membrane brings it down to 10-20.

My main question is can I use two cartridges of deion resin connected in line together? When deion resin expires does it release anything?

 

[cromag27]

You can get a single or dual di add-on. spectrapure has recently released new and improved di filters as well (mega maxcap and enduro di)

And yes, inline tds meters are not accurate at all. they're good for comparing values against one another, but that's it.

http://spectrapure.com/RO-RODI/ADD-ONS