Is this normal DI resin depletion?

TheEngineer · Sep 14, 2016

Could be increased CO2. I imagine it changes over time (just a guess though)

Squadir · Sep 14, 2016

If I am able to run an air pump in my source water before going into the unit would this work or does it gave to be aerated only after the ro membrane?

tom reilly · Sep 14, 2016

lazylivin said:
Caveat; I don't know a lot about ro/di units but I think something maybe wrong. I have TDS of about 220 going in to unit and di resin lasts me about 2,000 gallons. Going into DI tds is 2-4

My unit came with an inline valve to flush the membrane. I left in wrong position for 8 hours and results were what you have. Replaced resin and learned lesson.

TheEngineer · Sep 14, 2016

Squadir said:
If I am able to run an air pump in my source water before going into the unit would this work or does it gave to be aerated only after the ro membrane?

You want it after the RO membrane. Depending on your waste ratio, if you did it before you would need 20 gallons aerated to make 5. Aerate after the RO membrane and then pass it through the DI as the final step.

Squadir · Sep 15, 2016

icecool2 said:
You want it after the RO membrane. Depending on your waste ratio, if you did it before you would need 20 gallons aerated to make 5. Aerate after the RO membrane and then pass it through the DI as the final step.

will gravity feed be enough for the aerated water to pass through the DI stage or will need a pump?

TheEngineer · Sep 15, 2016

Gravity feed works for me. It is slow though.

Velcro · Sep 15, 2016

Gravity feed + aqualifter pump is good enough for me.

About the dye wearing off, I don't believe it. I've regenerated some resin many times and the change blue color is very minimal once it's recharged from the original blue.

CO2 used to be thought of as only a well water issue, but I have TONS of it in my city water. I went from 100 gallons per DI refill to 1000+.

Squadir · Sep 15, 2016

another thought.... will the RO product water be able to reach about 3' up?

Squadir · Sep 15, 2016

thinking about doing something like this, got the idea from on spectrapure's site.

TheEngineer · Sep 15, 2016

Squadir said:
another thought.... will the RO product water be able to reach about 3' up?

Yep.

blkhwkz · Sep 15, 2016

I have the Spectrapure 90GPD with 99% rejection RO membrane and booster pump. I just talked to Spectrapure at MACNA about my issues, I get about 150 gallons out of a SuperDI cartridge. With the new tank and my existing ones I will be doing at least 132 gallons of water changes a month, plus keeping DI water on hand I will be going through over 1 DI resin per month. Coming out of the tap is about 225 TDS and coming out of the RO membrane is 3. CO2 is at 8. I currently have the .5 micron sediment and the .5 micron carbon. Jeremy suggested I try the Pentek chloramine remover 1 micron carbon filter to see if that helps. I did test the tap water for ammonia and there was none, need to call the city water department and see if they are using chloramines or not.

TheEngineer · Sep 15, 2016

blkhwkz said:
I have the Spectrapure 90GPD with 99% rejection RO membrane and booster pump. I just talked to Spectrapure at MACNA about my issues, I get about 150 gallons out of a SuperDI cartridge. With the new tank and my existing ones I will be doing at least 132 gallons of water changes a month, plus keeping DI water on hand I will be going through over 1 DI resin per month. Coming out of the tap is about 225 TDS and coming out of the RO membrane is 3. CO2 is at 8. I currently have the .5 micron sediment and the .5 micron carbon. Jeremy suggested I try the Pentek chloramine remover 1 micron carbon filter to see if that helps. I did test the tap water for ammonia and there was none, need to call the city water department and see if they are using chloramines or not.

You could take your tap water to a lab for a quick screen. They're cheap. It cost me under $100.

Squadir · Sep 15, 2016

thank you for the help everyone, very much appreciated.

Thle009 · Sep 17, 2016

ZJedi945 said:
I am currently have similar issues with my BRS setup curious to see what people say. I filled up a 30gal brute and 1/4 of the DI is now brown.

Same problem here.

Squadir · Oct 11, 2016

Thanks alot guys!!!!! I made my degasification chamber and installed it, put in a new DI cartridge and boom!!! 90-100 gallons made so far and resin looks almost new still!!!! woot woot!! I'm really glad this worked.
this place is the best for advice!!

SVP · Oct 13, 2016

I have the spectrapure 90gpd unit. What helps mine and it's in the manual you get with the unit is I flush it for about 5 minutes before every use and another 3/5minutes after I get done with it. It helps flush out some of the particles that get filtered. My tds input is 250ppm after ro 1 or 2 tds and 0 tds after di unit. I have already ran 500 gallons I have a booster pump and I am at 60 psi and still have those numbers. Another thing that makes a difference is temperature of the water. Optimum temp is 75/79 degrees.

AZDesertRat · Oct 13, 2016

Actually the optimum temperature water is cold, the colder the better. 77 degrees is just a number they use in the industry to test one manufacturers membranes against another. It is a standard.
Colder water actually treats better since it is more dense or less viscous. Warmer water is more fluid so passes through the membrane easier carrying more dissolved solids along with it. The only advantage to warmer water is I makes water faster but I much prefer cold water and a booster pump to overcome the lower GPD due to the temperature.

SVP · Oct 18, 2016

AZDesertRat said:
Actually the optimum temperature water is cold, the colder the better. 77 degrees is just a number they use in the industry to test one manufacturers membranes against another. It is a standard.
Colder water actually treats better since it is more dense or less viscous. Warmer water is more fluid so passes through the membrane easier carrying more dissolved solids along with it. The only advantage to warmer water is I makes water faster but I much prefer cold water and a booster pump to overcome the lower GPD due to the temperature.

So in your opinion what is the optimum water temperature? 75/79 is pretty easy to get to, this definitely depends upon the season and where youl live. I live in Florida really hot in summer and beautiful in so called winter down here. Whereas if you live in the northern states and it is completely different.

AZDesertRat · Oct 18, 2016

In Phoenix mine out of the tap is 56-58 at times and I get the best rejection rate when it is that cold. When it gets up in the 70s and is more fluid the membrane does not work as well. I will take the colder water and a booster to overcome the temperature any day.

Buckeye Hydro · Oct 19, 2016

People confuse the standard membrane test temperature used by the manufacturers (25C, or 77F) with "optimum" temperature.

There really is no "optimum" temperature. Best just to understand what temperature does to the membrane performance and modify your situation/system accordingly.

Rejection increases (more pure RO water) at lower temperature

And assuming you hold the pressure steady,

Speed of production goes down at lower temperatures
Recovery goes down (more waste water) at lower temperatures

Russ