Improve the longevity of the DI resin

[sumant19]

I have a BRS 4-stage RODI system with water 150gpd water saver kit.

I observed that my DI resin gets depleted in about 4 months.

I understand water quality plays a major role in depleting the DI resin but wanted to see if there are any measures I can take to make it last a bit longer.

The total output of this system is about 10-15 gallons a week.
I do the RO membrane flush once a month for about 5 mins.
The RO membrane was changed in October 2022.
I change the other filters - sediment and carbon block with the DI resin. They were last changed in April 2024.


Interested in your opinions and experiences on this topic. Thank you!

 

[Cjtabares]

I am no expert, and not sure I can help, but from my understanding having the water saver connected in series will deplete the di media quicker.

So, I think, if you want to preserve your di resin, and don’t mind extra waste water, you could connect the ro filters in parallel.

 

[afboundguy]

I have the water saver add on kit and the TDS going into the DI resin went up which in turn depletes the DI resin faster. Mine only went up from 10ish to 15-20 so it wasn't horrible.

What are the prefilters and sizes you have before the RO membrane?

 

[TPhan]

Whats your tds coming in and after membranes? Like others said the second membrane will create more back pressure resulting in higher tds entering the resin. I always flush mine after and before each use. My tds is usually around 50 after the membrane at the start up. I flush it for a few minutes till it gets below 5 then run it through the DI. If u run all that tds through your DI all the time it will deplete faster. Adding a third resin by separating the cation and anion will also help. Depending on your source water, one will usually get used up before the other. By separatimg them you wont be wasting whatever thats not used up.

 

[dburr1014]

Can you run it longer per time? I think that helps.
Are you on a well? CO2 in the well depletes it really fast. I have seperate anion/cation and moxed bed. The anion gets recharged every 150ish gallons cuz the co2.
I use lye to recharge.

 

[afboundguy]

Are you running a 5 micron then 1 micron setup? And I would suggest changing out the prefilters more often as that will help in the long run and they are much cheaper.

I think I do a 5 micron prefilter and then a 5 micron carbon then 1 micron carbon before the membranes...

 

[sumant19]

Are you running a 5 micron then 1 micron setup? And I would suggest changing out the prefilters more often as that will help in the long run and they are much cheaper.

I think I do a 5 micron prefilter and then a 5 micron carbon then 1 micron carbon before the membranes...

1 micron sediment and 1 micron carbon

 

[sumant19]

Can you run it longer per time? I think that helps.
Are you on a well? CO2 in the well depletes it really fast. I have seperate anion/cation and moxed bed. The anion gets recharged every 150ish gallons cuz the co2.
I use lye to recharge.

Yup I am on well water... that plus the upgrade to the 150gpd water saver kit might have resulted in this. I upgraded to 150gpd kit in Mid-2023 and since then I observed that the DI resin started getting depleted earlier than before.

 

[sumant19]

Whats your tds coming in and after membranes? Like others said the second membrane will create more back pressure resulting in higher tds entering the resin. I always flush mine after and before each use. My tds is usually around 50 after the membrane at the start up. I flush it for a few minutes till it gets below 5 then run it through the DI. If u run all that tds through your DI all the time it will deplete faster. Adding a third resin by separating the cation and anion will also help. Depending on your source water, one will usually get used up before the other. By separatimg them you wont be wasting whatever thats not used up.

Thats a good suggestion!! .. my tds before the membrane is in 10s but never over 20s..

 

[this is me]

CO2 will kill it pretty quickly.
Incoming water tds should be no more than 3-4. Your RO should be able to do most of the work. Use high rejection RO that is 98% or better.
Measuring filter by time is not a good idea. In 4 months, I would’ve made about 400 gallons of water. I have two stage DI and the first time don’t last longer than 500gallons of water. Input of 4tds. I changed when the output of the first DI is 2tds. The last DI last a lot longer because it usually sees 0tds water.

 

[PSU4ME]

If you don’t run mixed resin but the 2 part with a mixed finishing cartridge, you only need to replace 1 stage which turns out to be cheaper. Think it’s the cation that burns first

 

[dburr1014]

If you don’t run mixed resin but the 2 part with a mixed finishing cartridge, you only need to replace 1 stage which turns out to be cheaper. Think it’s the cation that burns first

Anion, co2 kills the anion.
Lye will recharge it.