Reverse Osmosis & Deionization Q & A

[AquaFX]

The following is an answer to one of our customers who asked, How many gallons will my membranes last. So I thought I would post the answer.

Ahh, There is no direct answer to your question. There are several factors that determine membrane life.
Chlorine will destroy a membrane in no time flat. It is very import to keep your carbon up to date, if you think it maybe has a little time left on it, CHANGE IT.
A few more tips that will greatly extend your membrane life;

1. Don't run your membrane to lean, by cutting your waste stream to less than the recommendation. There are companies that tout their membranes need less waste, those companies sell a lot more membranes, because their customers destroy them. “Waste Water” is an integral part of the RO process, it is the vessel that removes the TDS. Technically, waste water, is called concentrate.
2. Scale is another enemy of membrane life. Running hard water will prematurely scale your membrane, rendering it useless. Softened water is ALWAYS better.
3. Heat; exposing your membrane to temperatures above 110 F will destroy it too.

With that said; the best answer maybe in our experience. We have had customers whose membranes have lasted 10 years; we have had customers trash their membranes in a few months. If you have questions, call us. We can help with your unique situation.

 

[dbl]

Nice write up and great advice.

 

[AquaFX]

Time for an update! We now have TRUE One to One Membranes. We are very fortunate to be working with one of the leaders in membrane technology. We have the 75 GPD in stock and are offering a discount for honest reviews. We have done our testing here, and we are thrilled with the results. We are producing 4 PPM TDS, which is about 1/2 of what our traditional membranes produced AND we always had some of the best membranes on the market! Give us a call and lets get reefing!

 

[AquaFX]

Update: We have the honor of working with one of the leaders in membrane technology. We are now able to offer TRUE One to One membranes. In in house testing, we have reduced our TDS by 1/2. We feel that this is excellent considering we had great rejection rates on our standard membranes.

We are happy to extend an offer to try one of these membranes at a reduced rate for an honest review.

 

[TMB]

Update: We have the honor of working with one of the leaders in membrane technology. We are now able to offer TRUE One to One membranes. In in house testing, we have reduced our TDS by 1/2. We feel that this is excellent considering we had great rejection rates on our standard membranes.

We are happy to extend an offer to try one of these membranes at a reduced rate for an honest review.

1:1 rejection sounds awesome, as well as possible lowered TDS output. I'd be interested in trying 2 of these in my system.
Let me tell you what I have going on currently:
900 incoming TDS (water in AZ is pretty bad!)
3 stage whole home filter system - Sediment filter > Carbon filter > Softener
Spectrapure 180 GPD system with autoflush and booster pump @80 PSI.
This system has the standard sediment filter and carbon blocks (which is now the second time because of the whole home filters)
With the high rejection rate membranes @ 3:1 from SP the very best I can get output wise is about 17 - that's 98.11.
I'm also running the BRS seperate bed DI because of the very fast rate that my water exhausts the anion resin.
So the three stage DI goes Cation bed - Anion bed - Mixed bed.

I wouldn't expect to gain much in the way of rejection, but if I could lower water consumption to 1:1, and have a reasonable membrane life that would be a huge plus for me. My reef system is right at about 500 gallons, and evap is about 25 - 28 gallons per week. I also have an auto water change system that changes 5 gallons per day. I also do another 50 gallon water change every other week just for clean up purposes. So, my monthly usage is about 370 gallons of DI water.

Let me know if you think your membranes would be a good fit for my system/needs. Thanks.

 

[AquaFX]

1:1 rejection sounds awesome, as well as possible lowered TDS output. I'd be interested in trying 2 of these in my system.
Let me tell you what I have going on currently:
900 incoming TDS (water in AZ is pretty bad!)
3 stage whole home filter system - Sediment filter > Carbon filter > Softener
Spectrapure 180 GPD system with autoflush and booster pump @80 PSI.
This system has the standard sediment filter and carbon blocks (which is now the second time because of the whole home filters)
With the high rejection rate membranes @ 3:1 from SP the very best I can get output wise is about 17 - that's 98.11.
I'm also running the BRS seperate bed DI because of the very fast rate that my water exhausts the anion resin.
So the three stage DI goes Cation bed - Anion bed - Mixed bed.

I wouldn't expect to gain much in the way of rejection, but if I could lower water consumption to 1:1, and have a reasonable membrane life that would be a huge plus for me. My reef system is right at about 500 gallons, and evap is about 25 - 28 gallons per week. I also have an auto water change system that changes 5 gallons per day. I also do another 50 gallon water change every other week just for clean up purposes. So, my monthly usage is about 370 gallons of DI water.

Let me know if you think your membranes would be a good fit for my system/needs. Thanks.

Yes, you do have some demanding water. The softener is a great help to membrane life. I do not see any reason that we would not have good success, and this sure will be a test. If you would like to give us a call 407-599-2123, I am looking forward to your results.

 

[TMB]

Well, I just placed an order for 2 new membranes and new flow restrictors. (these were not free to me, so everyone can expect me to post honest results). That last statement should probably be a given, but I wanted to be transparent about this.
I'm curious to know if the restrictors will be set for a 1:1 rejection? I guess I'll find out when I set it up and test.
When I set this up I plan to test:
Permeate/Concentrate ratio
Incoming TDS
Membrane output (permeate) TDS, as well as flow GPD.
Rejection %
I also already have all new .5 micron sediment and carbon filters that I will replace when I install the new membranes.
Looking forward to seeing how this works out!

TMB

 

[AquaFX]

TMB, we are also learning the flow restrictors and how the "standard" restrictors behave with this new membrane technology . I am going to put an adjustable restrictor in your order in case you need it.

 

[Salty Lemon]

Thank you for this thread -- even though the original was posted almost a year ago. I am having issues with exactly what is being discussed here. Your thread has already answered many of my questions. And @TMB , I live in AZ too -- which is why I'm having the same issues you mentioned earlier. Thanks for your input as well.

 

[AquaFX]

Thank You Salty Lemon!

 

[AquaFX]

Thank you for this thread -- even though the original was posted almost a year ago. I am having issues with exactly what is being discussed here. Your thread has already answered many of my questions. And @TMB , I live in AZ too -- which is why I'm having the same issues you mentioned earlier. Thanks for your input as well.

Thank YOU Salty Lemon

 

[Merv Himself]

The following is an answer to one of our customers who asked, How many gallons will my membranes last. So I thought I would post the answer.

Ahh, There is no direct answer to your question. There are several factors that determine membrane life.
Chlorine will destroy a membrane in no time flat. It is very import to keep your carbon up to date, if you think it maybe has a little time left on it, CHANGE IT.
A few more tips that will greatly extend your membrane life;

1. Don't run your membrane to lean, by cutting your waste stream to less than the recommendation. There are companies that tout their membranes need less waste, those companies sell a lot more membranes, because their customers destroy them. “Waste Water” is an integral part of the RO process, it is the vessel that removes the TDS. Technically, waste water, is called concentrate.
2. Scale is another enemy of membrane life. Running hard water will prematurely scale your membrane, rendering it useless. Softened water is ALWAYS better.
3. Heat; exposing your membrane to temperatures above 110 F will destroy it too.

With that said; the best answer maybe in our experience. We have had customers whose membranes have lasted 10 years; we have had customers trash their membranes in a few months. If you have questions, call us. We can help with your unique situation.

Great advice. Can you recommend a good TDS gauge?

 

[AquaFX]

A GOOD TDS meter would be a conductivity meter, but they are a bit expensive. The hobby meters are all very similar. The error is +/- 2% of scale. I have found when they are calibrated at a very low TDS level they stay pretty true. Some meters have temp compensation, but our water stays the same temperature most of the time, so not really needed.

A wikipedia reprint "To obtain an approximate sodium chloride TDS value, multiply the ECreading (in microSiemens/cm) by 1000 and divide by 2. To get an EC value, multiply the ppm reading by 2 and divide by 1000. Thus, if your EC is 1: 1*1000/2= 500 ppm" so you can see the reading are much more precise with conductivity.

Very few folks need that much accuracy in our hobby. Hope I didn't go too far off track ;Hilarious

 

[Merv Himself]

Hope I didn't go too far off track ;Hilarious

Not at all. Great information. And thank you! Most people don't have the patience to research things as deeply as they should these days. Your knowledge is greatly appreciated.

 

[shadow1013]

AquaFX any update on the new membrane? Also TMB mentioned BRS has a 3 part DI add-on that breaks the DI up into the two separate and then a mixed, can you do that as well?

A GOOD TDS meter would be a conductivity meter, but they are a bit expensive. The hobby meters are all very similar. The error is +/- 2% of scale. I have found when they are calibrated at a very low TDS level they stay pretty true. Some meters have temp compensation, but our water stays the same temperature most of the time, so not really needed.

A wikipedia reprint "To obtain an approximate sodium chloride TDS value, multiply the ECreading (in microSiemens/cm) by 1000 and divide by 2. To get an EC value, multiply the ppm reading by 2 and divide by 1000. Thus, if your EC is 1: 1*1000/2= 500 ppm" so you can see the reading are much more precise with conductivity.

Very few folks need that much accuracy in our hobby. Hope I didn't go too far off track ;Hilarious

 

[DesertReefT4r]

1:1 rejection sounds awesome, as well as possible lowered TDS output. I'd be interested in trying 2 of these in my system.
Let me tell you what I have going on currently:
900 incoming TDS (water in AZ is pretty bad!)
3 stage whole home filter system - Sediment filter > Carbon filter > Softener
Spectrapure 180 GPD system with autoflush and booster pump @80 PSI.
This system has the standard sediment filter and carbon blocks (which is now the second time because of the whole home filters)
With the high rejection rate membranes @ 3:1 from SP the very best I can get output wise is about 17 - that's 98.11.
I'm also running the BRS seperate bed DI because of the very fast rate that my water exhausts the anion resin.
So the three stage DI goes Cation bed - Anion bed - Mixed bed.

I wouldn't expect to gain much in the way of rejection, but if I could lower water consumption to 1:1, and have a reasonable membrane life that would be a huge plus for me. My reef system is right at about 500 gallons, and evap is about 25 - 28 gallons per week. I also have an auto water change system that changes 5 gallons per day. I also do another 50 gallon water change every other week just for clean up purposes. So, my monthly usage is about 370 gallons of DI water.

Let me know if you think your membranes would be a good fit for my system/needs. Thanks.

Wow Im in Mesa also and my tap is 475 ppm. 900 is crazy high! I would love to come see your 500g reef sometime.