How far to chase RO water for a high-end SPS tank.

[Reefer1978]

Youve done everything right then! Next thing I would suggest is check with BRS. They know their units well and if you have good pressure you should seen near the advertised rejection rate. Currently you’re over 5x that so something HAS to be wrong!

Agreed, and I wish they were open on the weekend. Advertised rejection rate is 3:1, with 96% removal, and I am at 5:1, with 90% removal at best... so it aint right. But, I can tell you the answer from BRS right now before I even call tomorrow (these are ideal numbers)

 

[Reefer1978]

This is a possibility but not sure what the pressure drop would be along the way. You’d need a inline gauge to see.

Ohh True... I didn't think of that...

 

[Reefer1978]

@spsick another thing I remember from good old days is heating water pre-RO. Would that help in your opinion?

 

[spsick]

Agreed, and I wish they were open on the weekend. Advertised rejection rate is 3:1, with 96% removal, and I am at 5:1, with 90% removal at best... so it aint right. But, I can tell you the answer from BRS right now before I even call tomorrow (these are ideal numbers)

This is throwing me off. Are you just measuring your reject to get the ratio? awesome.

Silly thing but check and make sure the new unit doesn’t have the wrong flow restrictor on it? Or if it’s the flushing type that it’s not open.

 

[spsick]

@spsick another thing I remember from good old days is heating water pre-RO. Would that help in your opinion?

Tempering helps with production volume but I don’t know that it improves output quality

 

[Reefer1978]

This is throwing me off. Are you just measuring your reject to get the ratio? awesome.

Silly thing but check and make sure the new unit doesn’t have the wrong flow restrictor on it? Or if it’s the flushing type that it’s not open.

Yep, I ran dirty and clean into 2 separate buckets to get the measurements, eye-ball it was 4:1. I then ran them into wife's cooking measuring cups for 30 seconds each line. Clean came in at 105ml, dirty was right under 500. So close to 5:1, prob 4.8:1 is the ratio.

Yeah it's one of those valves with restrictor in one, I did also buy the needle valve as recommended above, but realized I don't have enough splitters to build my own bypass, so that's not on the unit yet.

 

[Reefer1978]

Tempering helps with production volume but I don’t know that it improves output quality

I did some additional reading actually seems to reduce it (at least when it comes to salt rejection rate), so I am leaving it cold for now.

 

[Tired]

Are you able to send a sample off for testing to find out what that 2 tds /is/? Since I'd imagine there are things it could be that would be harmless.

 

[Reefer1978]

Are you able to send a sample off for testing to find out what that 2 tds /is/? Since I'd imagine there are things it could be that would be harmless.

I am already at 0, and I know how to get there... what I am trying to figure out, if it's possible not to burn though DI. If the only option is to keep burning DI, then that's what it is. Reason for 2 TDS but DI coming to the end of life.

 

[Randy Holmes-Farley]

And last question, given PH is already this high, would aerating help? ok, time for coffee.

I can't see a scenario where lowering the pH of tap water would give better RO/DI performance. At low pH, many neutral molecules (carbonic acid, silicic acid) can pass a membrane and deplete the di faster, but I don't see that happening to tap water at higher pH, except for ammonia, which may be an issue, but cannot be causing multiple ppm of TDS.

 

[spsick]

Yeah it's one of those valves with restrictor in one, I did also buy the needle valve as recommended above, but realized I don't have enough splitters to build my own bypass, so that's not on the unit yet.

And just to be clear the flush valve handle is perpendicular to the flow right? Trying to eliminate any possible cause here.

 

[SteveMM62Reef]

Would it be Cheaper to have “Spring” Water Delivered to your house and run it through your RO/DI? Know anyone that goes to New York City, on a regular bases? The water was so pure in the city it ate up Solenoid Valves on our Computer Room Humidifiers. Also to get a Steam Electronic Humidifier Cannister working, we would have to add Salt or an Alkseltzer Tablet. BTW, in New York City that was over twenty years ago, so it may have changed.

 

[Reefer1978]

And just to be clear the flush valve handle is perpendicular to the flow right? Trying to eliminate any possible cause here.

yup it’s closed

Would it be Cheaper to have “Spring” Water Delivered to your house and run it through your RO/DI? Know anyone that goes to New York City, on a regular bases? The water was so pure in the city it ate up Solenoid Valves on our Computer Room Humidifiers. Also to get a Steam Electronic Humidifier Cannister working, we would have to add Salt or an Alkseltzer Tablet. BTW, in New York City that was over twenty years ago, so it may have changed.

No, wouldn’t be cheaper. The math is actually pretty simple... Using bulk DI resin, cost it approximately $11 to make 55g. With spring water picked up at the store (delivery is even more), it's about $9 for the same amount of water. Taking it then through RO, even with 1:1 rejection rate, would make it $18.

 

[Reefer1978]

Before I go to NYC to collect water, I might as well look up in the sky and go for Rain Water

 

[Reefer1978]

Small update if anyone is interested, or needs a way to resolve a similar issue in NJ. Water softener was installed on Friday. Post membrane TDS is now 10 (this is down from 600 that's coming into the house).

 

[spsick]

Small update if anyone is interested, or needs a way to resolve a similar issue in NJ. Water softener was installed on Friday. Post membrane TDS is now 10 (this is down from 600 that's coming into the house).

Great news!

 

[Reefer1978]

Great news!

Multi thousand dollar great news, but yes, at least it's figured out Thanks @spsick !!!

 

[Troylee]

Multi thousand dollar great news, but yes, at least it's figured out Thanks @spsick !!!

I’m in the same boat in Vegas… tds at 570 going into my membrane but comes out around 7… still eats up di resin fast but i do get 0 tds after 2 large di cannisters.. after having the hard water erode some copper pipe in my wall and cause a leak I’m thinking it’s time to get a water Softner myself… ugh.. a water Softner is much cheaper than these repairs and the plumbers only give you a 30 day warranty because our water is so hard and corrosive lol..

 

[Randy Holmes-Farley]

Small update if anyone is interested, or needs a way to resolve a similar issue in NJ. Water softener was installed on Friday. Post membrane TDS is now 10 (this is down from 600 that's coming into the house).

You are suggesting that a water softener added before the RO/DI reduced the TDS coming out of the membrane (before DI) ,without any change or maintenance on the membrane itself?

That's not what I would expect. Softened water should get through an RO membrane a little bit better, but it also preserves mambrane life by reducing calcium carbonate precipitation onto and into it.

 

[Reefer1978]

I’m in the same boat in Vegas… tds at 570 going into my membrane but comes out around 7… still eats up di resin fast but i do get 0 tds after 2 large di cannisters.. after having the hard water erode some copper pipe in my wall and cause a leak I’m thinking it’s time to get a water Softner myself… ugh.. a water Softner is much cheaper than these repairs and the plumbers only give you a 30 day warranty because our water is so hard and corrosive lol..

Yeah that's pretty nasty!!!