DI resin. High TDS

[workhz]

Not entirely sure how my resin has been used up but after less than 300 gallons in about 4 months, it’s done. TDS spiked to 8 out of a 6 stage system. Before the rodi it’s about 4.
I have a feeling it’s because I make less than a gallon at a time. So will add a bypass in the future to make sure TDS is low before it gets to the DI.

Have some resin from BRS ordered. Won’t get here till next week and I need some top off water.

was planning on just getting the water pre DI at a tds of 4. System is a 90. 5 gallons should last me a week.

think it’s ok putting 5 gallons of 4 tds into the system? All soft and lps. No sps.

 

[Mike konesky]

I'd buy distilled, ask a local reefer, or buy a gallon from a lfs. Unless you know what that 4tds is, I wouldn't do it.

 

[workhz]

Yeah, I kinda landed there too. Just going to get distilled

 

[LeftyReefer]

Do you have a TDS meter between your RO and DI ?

First thing I did after putting in my new RODI was also putting in a new DI bypass valve.
It only costs $20 and allows you to flush and dump all that high TDS water out of the RO membrane instead of sending it through your DI canister every time.

Now, before and after I run my RODI, I just turn the flush valve on and flip the DI bypass to divert the water to a drain. do this for 2-3 minutes and the TDS coming out of the RO drops to 1 TDS. At that point, close the flush valve and flip the DI bypass valve to divert water back to the DI canister and you're back to making 0 TDS water again and only putting low TDS water into the DI. Should save on DI resin over the long run.

 

[workhz]

yeah, I have a TDS meter on both sides. I still need to add a bypass valve before the DI.

 

[Randy Holmes-Farley]

yeah, I have a TDS meter on both sides. I still need to add a bypass valve before the DI.

Yes, making a gallon at a time is inefficient since salts creep across the RO membrane any time it is just sitting around. That's often called TDS creep, and makes the first gallon use up a lot of resin capacity each time you turn it on.