TDS Reading after RODI system...

[ReefSapper]

Just curious what readings you guys are getting and confirming what i have is no cause for concern. As of now everything in all of my tanks is going well and the water has not been an issue. We recently installed the BRS TDS meter, we placed 1 probe just after the RO membrane and the other after the DI chamber. Going into the RO we are reading about 25-30 ppm after things settle out but after the DI chamber we are still getting between 2-4ppm. I was expecting to see 0 but as low as it is i am not worried, this is the BRS 4 stage unit, RO membrane is only a couple months old and all filters are fairly new as well. Another factor is i live in Phoenix and our water here is as bad as you will find in the country so i am sure the incoming TDS is off the charts but i have not checked it. Thoughts?

 

[littlebeard]

Have you flushed the RO membrane?

What is your tap water TDS?
I have the 5 stage BRS.

Tap water is about 300-400ppm TDS.
After RO 2-4ppm
After DI 0 ppm.

 

[SPR1968]

Have you changed the DI resin, it can become spent fairly quickly depending on production rate etc

 

[Rubberfrog]

Just curious what readings you guys are getting and confirming what i have is no cause for concern. As of now everything in all of my tanks is going well and the water has not been an issue. We recently installed the BRS TDS meter, we placed 1 probe just after the RO membrane and the other after the DI chamber. Going into the RO we are reading about 25-30 ppm after things settle out but after the DI chamber we are still getting between 2-4ppm. I was expecting to see 0 but as low as it is i am not worried, this is the BRS 4 stage unit, RO membrane is only a couple months old and all filters are fairly new as well. Another factor is i live in Phoenix and our water here is as bad as you will find in the country so i am sure the incoming TDS is off the charts but i have not checked it. Thoughts?

I'm in the east valley. I'll be setting up their 6 stage deluxe next week. I'll let you know what readings I get.

 

[ReefSapper]

Have you flushed the RO membrane?

What is your tap water TDS?
I have the 5 stage BRS.

Tap water is about 300-400ppm TDS.
After RO 2-4ppm
After DI 0 ppm.

I flush it regularly, not every use but just about. Not sure the tap TDS but i am sure it is outrageous.

Have you changed the DI resin, it can become spent fairly quickly depending on production rate etc

Yes i go through it fairly quick, we are running three tanks and a quarantine so between top off and water changes the resin goes quick. I use the color changing stuff from BRS but the TDS meter was mainly a way to confirm what the color change was telling us.

I'm in the east valley. I'll be setting up their 6 stage deluxe next week. I'll let you know what readings I get.

I am in Chandler, just easier to say Phoenix lol. And yes i would be curious to hear what your readings are so thanks in advance for sharing.

 

[Phil D.]

Hi ReefSapper!! I live in Gilbert and I have the water save kit from BRS , (2 RO membranes), and dual DI. Out of the faucet I get 475 TDS, out of the membranes I get 6 TDS and out of the 2nd stage DI 0. Do you have a single or dual DI?

 

[Rubberfrog]

I flush it regularly, not every use but just about. Not sure the tap TDS but i am sure it is outrageous.

Yes i go through it fairly quick, we are running three tanks and a quarantine so between top off and water changes the resin goes quick. I use the color changing stuff from BRS but the TDS meter was mainly a way to confirm what the color change was telling us.

I am in Chandler, just easier to say Phoenix lol. And yes i would be curious to hear what your readings are so thanks in advance for sharing.

I'm in Gilbert. No one outside of the area has heard of us. Haha

 

[ca1ore]

Just curious what readings you guys are getting and confirming what i have is no cause for concern. As of now everything in all of my tanks is going well and the water has not been an issue. We recently installed the BRS TDS meter, we placed 1 probe just after the RO membrane and the other after the DI chamber. Going into the RO we are reading about 25-30 ppm after things settle out but after the DI chamber we are still getting between 2-4ppm. I was expecting to see 0 but as low as it is i am not worried, this is the BRS 4 stage unit, RO membrane is only a couple months old and all filters are fairly new as well. Another factor is i live in Phoenix and our water here is as bad as you will find in the country so i am sure the incoming TDS is off the charts but i have not checked it. Thoughts?

Assume you mean 25-30 after the RO (not going into it)? Most RO membranes reject between 95 and 99%, so that seems high to me unless your raw water is essentially a solid. 25-30 will eat a mixed DI canister pretty quickly.

Chez moi, about 450 going into the RO, about 6 out of the RO, then 0 after the cation and anion DI stages. Cation lasts a very long time, anion lasts about 500 gallons.

 

[ReefSapper]

Hi ReefSapper!! I live in Gilbert and I have the water save kit from BRS , (2 RO membranes), and dual DI. Out of the faucet I get 475 TDS, out of the membranes I get 6 TDS and out of the 2nd stage DI 0. Do you have a single or dual DI?

Just the single, that's probably why i am getting a 2ppm reading but i am really not overly concerned with such a low number, should i be?

 

[ReefSapper]

Assume you mean 25-30 after the RO (not going into it)? Most RO membranes reject between 95 and 99%, so that seems high to me unless your raw water is essentially a solid. 25-30 will eat a mixed DI canister pretty quickly.

Yes i did mean after sorry for the confusion, i thought that seemed high as well but the membrane is less than 4 months old so not sure what would be the cause. It's flushed for about 60 seconds almost every use.

 

[Phil D.]

Just the single, that's probably why i am getting a 2ppm reading but i am really not overly concerned with such a low number, should i be?

With just a single RO and single DI, the 2 tds is what i would expect. With the 2 RO membranes I am getting a ratio of 1:1.3 meaning 1 gallon of product to 1.13 gallons of waste. I would recommend getting the saver kit and adding another DI.

 

[ca1ore]

Never lived in AZ, but perhaps the water TDS is that high. I always seem to be wrestling with my RODI system, so I sympathize LOL.

 

[Oregon Grown Reef]

The best thing I did for making my own water was get the BRS 7-stage unit with the water saver upgrade, and I live in a city where the TDS coming from tap is as low as 20 (it's been awhile since I tested it). My single mixed bed DI resin would get spent quickly, which I got tired of real quick. If you can swing it, you can pick up a triple DI resin package from BRS for a decent price. In my opinion, a booster pump is also essential. I'm currently making 200+ gallons a day of 0 TDS. After a year, I'm finally at a point where my mixed bed DI resin needs to be changed out. I'm still getting 0 TDS, but I'm gonna swap it before it starts creeping. With high TDS water like yours it would obviously get spent faster, but you'll be able to make water faster and replace resin less often. Of all of the pricey things we buy for our tanks, the 7-stage RODI water saver is by far the best and IMHO essential.

 

[Uncle99]

Out of the tap 180
Out of membrane 5
Out of DI 0.

If you don’t get below say 10 after membrane, your going to spend a fortune on resins.

 

[ReefSapper]

Thanks for all the replies! I think you are correct, seems silly to spend all the money i have and continue on the hobby and not have the water saver kit....sometimes we are pretty silly in the way we choose to 'save money' lol. "yeah its fine to buy that $200 gold torch" and hour later "They want $60 for the water saver!!! Heck no i wont do it" LOL.