BRS color changing DI resin

lion king · Jul 9, 2017

I love brs; their products, customer service, and info. So I am bit confused why they haven't responded to my inquiry about the color changing DI resin. I've been running a brs value 4 stage RO system for over 5 years now. Less than 2 years ago I replaced the RO membrane so I'm sure that has no issue.

I make no more than 200g a month, tds is in the low 400s going in and my routine to changing filters are as follows. When my tds out starts to register I change the DI resin, then the next time tds rises I change all 3 filters. This had been working well but at about the first of the year I started to notice a change.

The color changing DI resin is now expired after about a month, approximately 200g. Does this seem right or do you think I am having some sort of issue. I asked BRS if they had changed the formulation of the resin, but I have not gotten any response.

Fishfinder · Jul 9, 2017

do you have a TDS meter before your DI/after your RO?
city water or well?

lion king · Jul 9, 2017

Fishfinder said:
do you have a TDS meter before your DI/after your RO?
city water or well?

It's in the post: low 400s before; 0 after, I change filters when it rises from 0. City water and yes there are chloramines, even though they lie whenever they get the chance. But the bigger point is the change in efficiency. I was just wondering if anyone else has seen a difference. I used to go at least 3 months, maybe it's a change in my city's water chemistry if no one else has seen a difference.

SashimiTurtle · Jul 9, 2017

400 tds before is a little high, so it'll be harder on filters membranes and DI resin. It should always read 0tds after the DI but are you saying you get 0 tds after your RO and before your DI? My inlet tds is usually 80-90, after the RO is 2-4 and the DI brings it to 0. I'm guessing you don't really have 0 tds coming out of your RO.

Fishfinder · Jul 9, 2017

It's a little confusing, I was trying to clarify. Is it 400 going into the RO membrane? What is the reading going into the DI?

Ocelaris · Jul 9, 2017

What you're getting now sounds more in line with what you're supposed to be getting. The point of the color changing resin is to tell you that it's depleted. So blue is good, yellow is bad. Do you use that as a guide? I change the three pre-filters every 6 months without question, di when the first is spent, I swap the first and second di resin chambers and refill the spent one.

You would probably do well to get the three stage tester, so you can see before ro, after ro, and after di stages. That way you know you're ro membrane is working properly.

I have about 350 going in, softened water. I get about 5 tds coming out, and I get probably 150 gallons or so to a di chamber. So I would say you probably are about right now.

Brs sometimes takes a while to get back, but di resin is pretty standard and I am almost 100 percent sure they didn't change anything. I would first get that triple tds meter they sell, and that should confirm/deny your assumptions about the ro membrane being fine.

Also has your pressure dropped? A lot of things can affect output and efficiency, but I suspect brs doesn't have anything to do with it.

lion king · Jul 9, 2017

Ocelaris that's exactly what I was getting at. I don't have a 3 point tds meter, only 2 before and after. It would be good to be able to check right after membrane to verify I'm good. What bothers me is that I had been getting after double that, but by your calculations I'm about right. My pressure is consistent but I can't verify if my input water chemistry has changed. I have a very sensitive sense of smell and can smell the chlorine in tap water at times. I don't smell anything now but that doesn't mean they haven't cranked up their treatment.

Ocelaris · Jul 9, 2017

Can you swap the tds meter points? Honestly I wouldn't bother measuring after the di resin if you have the color changing.

Unless they switched sources, it's unlikely that chloramines will affect the output. Incoming tds, temp, pressure and the "hard water" minerals like calcium, magnesium, and carbonates etc would more likely change your output.

I didn't recall hearing about your pressure, any chance you could measure that? New neighbor with a sprinkler system?

lion king · Jul 9, 2017

We have hard water, tds has always been low to mid 400s from when I first installed the unit. Pressure is at 80psi, not sure that that's changed either. Something is definitely going on; I would be disappointed if the ro membrane is failing already, less than 2 years. I looked at swapping the feed from the tds meter, looks like a pita. I would like to get a reading after the ro membrane; we'll see.

Ocelaris · Jul 9, 2017

The only other suggestion I have is to try a flush valve when you start up making water. When I make water I try to do as much as possible to make sure that the di resin lasts longer. It takes a good five minutes for my tds to drop from 10 to 5 when I start it up. Small batches use di faster as the tds is higher at the beginning.

lion king · Jul 9, 2017

I use a flush valve and never make small batches, I'd say never less than 20g at a time, my reservoir is 32g.

I guess I could get one of these to install after the ro membrane. https://www.bulkreefsupply.com/single-inline-tds-meter-sm-1-hm-digital.html

Water Dog · Jul 9, 2017

I don't put too much stock in the color change of the DI resin. I trust the TDS meter. I've had a DI canister continue to produce 0 TDS water for quite some time after the resin looked to be exhausted. Now I just get the cheaper non color changing resin and rely on my meters to tell me when it's time to replace.

Ocelaris · Jul 10, 2017

Water Dog said:
I don't put too much stock in the color change of the DI resin. I trust the TDS meter. I've had a DI canister continue to produce 0 TDS water for quite some time after the resin looked to be exhausted. Now I just get the cheaper non color changing resin and rely on my meters to tell me when it's time to replace.

That's a good idea if you could monitor it while making batches, but I typically make 30+ gallons at a go, set it and forget it. So I'd worry it'd leave tds in a batch. I wonder how hard it would be to rig up a solenoid to trigger off the tds meter once it starts registering zero.

The color changing resin is only half of the resin, I forget whether it's the acid or base type, but I've seen the same results with my dual di chambers. I only change the first cannister once the second starts to deplete. That way I'm fully using the di resin completely. However the OP only has one di resin cannister.

lion king · Jul 17, 2017

So I got the tds meter installed after the ro membrane. I'm getting 29, by the standards of my membrane I should getting no more than 17. The minimum rejection rate is 96%, tds going in is 425. Do you think it's time to change the ro membrane, I have a new one being delivered today.

Ocelaris · Jul 17, 2017

That doesn't seem that bad. 396/425= 93 percent. Seems pretty accurate for theoretically maxing out 3 percent higher.

On another note, the color changing resin isn't really that accurate. I did another 30 plus gallons with my first filter completely discolored, and it hasn't even started to change the other cartridge. So good lesson learned!

Fishfinder · Jul 17, 2017

TDS of 29 will burn DI fast. It's hard because we don't know what the post RO TDS used to be, can't tell if it's a change.

I was having water issues for a long time. I had a post RO TDS of 50 and I was using a DI canister every 40-50 gal

lion king · Jul 23, 2017

Installed the new membrane, now we're talking; tds in 436, after membrane 8. Beats the heck out of 29, so I should see a good increase in the life of my di resin. Only got 2 years out of this membrane, but I know mid 400s tds going in is high and I'm not really sure how much water I'm making on a consistent basis.