Help with RO/DI

[-Logzor]

I have a 150 GPD RO/DI system. It has a two RO membranes (BRS Water Saving Upgrade) followed by two DI canisters.

I installed two new membranes at the end of December. I also installed the second DI canister in December. The first DI resin canister was in good shape at the time, so I didn't swap it. I figured that it would extinguish first. I noticed the 2nd canister going brown, then the first.

Now both DI are totally brown and the TDS coming out of the system is 32.

I tested every point on the system to try to find the issue, thinking I probably had hooked it up incorrectly:

Tap: 180
Waste: 225
Finished Water: 32

After 1st and 2nd membrane: 3.7
After 1st membrane: 1.8 (waste was 172)
After 2nd membrane: 3.6 (waste of both - 225 - same thing as total waste)
After 1st DI: 8
After 2nd DI 32 (same thing as finished water)
Waste: 225

I've never had DI extinguish this fast. I have a 150g aquarium and probably do a 30g water change every other week. Plus ATO water on the display and a QT system. What could be the issue here?

The good water out of my 2nd membrane is worse the the first. Assuming this is a pressure issue?

The water straight out of the membranes is better than out of either the 1st or 2nd DI?

The water out of the 1st DI is better than out of the 2nd.

It looks like the DI is adding TDS to my water, how is this possible?

 

[AZDesertRat]

Was the DI resin factory fresh in an unopened vacuum sealed mylar foil bag or was it bulk resin you had on hand? If it is bulk was it stored properly and for less than 6 months?

One thing to keep in mind is color changing resins contain dyes that register as TDS when it wears off the resin and goes into the treated water. Not a huge amount but it does register. I never recommend color changing as it can be very unreliable.
I also don't fall for the water saver bunk with dual membranes, it's not that easy. Think about it for a minute, you are sending the concentrated waste from the first membrane into the second so it is even more important you keep the waste ratio at 4:1 for the membranes to last. Unfortunately some vendors have a lot to learn. Notice none of the other vendors, many who have been around for 25 years or more, promote dual membranes as a water saver? That should be a red flag in my book. It doesn't work line that, not for long anyway.

 

[-Logzor]

Was the DI resin factory fresh in an unopened vacuum sealed mylar foil bag or was it bulk resin you had on hand? If it is bulk was it stored properly and for less than 6 months?

One thing to keep in mind is color changing resins contain dyes that register as TDS when it wears off the resin and goes into the treated water. Not a huge amount but it does register. I never recommend color changing as it can be very unreliable.
I also don't fall for the water saver bunk with dual membranes, it's not that easy. Think about it for a minute, you are sending the concentrated waste from the first membrane into the second so it is even more important you keep the waste ratio at 4:1 for the membranes to last. Unfortunately some vendors have a lot to learn. Notice none of the other vendors, many who have been around for 25 years or more, promote dual membranes as a water saver? That should be a red flag in my book. It doesn't work line that, not for long anyway.

It was factory sealed from BRS and I packed it myself. So I'm fairly certain the resin was good to begin with. Never know the dye could cause a TDS reading! What resin do you recommend?

I picked up the second membrane years ago from BRS. I'm concerned it frying my DI resin faster than normal since my waste ratio is closer to 1:1 than 4:1.

I ended up calling Russ from Buckeye Hydro. He walked me through the system to try and pinpoint the issue. Turned out I hadn't packed my canister well enough and they fluidized. I had issues with the new canister from BRS. It was really difficult to get it packed. Not sure what happened with my original, but it had a gap as well (also fluidized).

 

[AZDesertRat]

DI resin shrinks slightly as it is used, this is why you pack it tightly and use the foam donut ring in the top.

After using them all I now use only Spectrapure exclusively, they custom blend all their own resins based on thousands of hours of testing. It really makes a difference. And I don't but bulk resin anymore since a cartridge lasts like 5-8 times longer than it did with bulk resin no matter how fresh or who I purchased it from.

To pack a cartridge with bulk or loose resin I fill it to the top, tap the cartridge on the counter or table top sharply several times to pack it down, refill, tap, refill, tap then scrape just enough off the top to squeeze the foam ring in snugly. If any resin is left I use a seal a meal vacuum sealer on it then place it in the back of the refrigerator to be used in the next 3 months or it starts going bad.
You are speaking with a very knowledgeable vendor with Russ, let him help you get the waste ratio straightened out or you will be buying new membranes soon. Also if you have a Water softener, make sure to use softened water, all membrane manufacturers recommend it. Best thing you can do for a membrane!

 

[-Logzor]

DI resin shrinks slightly as it is used, this is why you pack it tightly and use the foam donut ring in the top.

After using them all I now use only Spectrapure exclusively, they custom blend all their own resins based on thousands of hours of testing. It really makes a difference. And I don't but bulk resin anymore since a cartridge lasts like 5-8 times longer than it did with bulk resin no matter how fresh or who I purchased it from.

To pack a cartridge with bulk or loose resin I fill it to the top, tap the cartridge on the counter or table top sharply several times to pack it down, refill, tap, refill, tap then scrape just enough off the top to squeeze the foam ring in snugly. If any resin is left I use a seal a meal vacuum sealer on it then place it in the back of the refrigerator to be used in the next 3 months or it starts going bad.
You are speaking with a very knowledgeable vendor with Russ, let him help you get the waste ratio straightened out or you will be buying new membranes soon. Also if you have a Water softener, make sure to use softened water, all membrane manufacturers recommend it. Best thing you can do for a membrane!

That's interesting about the DI resin. So you buy a new canister every time (including the housing)?

So I just repacked my DI canister and removed the second canister from the system (I only had one refill). Water is passing through the canister just fine, but my filter housing is not filled up completely with water. Is this a problem (I'll post a picture via tapatalk in the next post)?

 

[-Logzor]

 

[AZDesertRat]

You are confusing the canister with the cartridge. The canister is the opaque or clear housing with a lid that unscrews and holds the cartridge which the resin is packed in. I replace the cartridge but reuse the canister.
The air in the canister does not matter. The cartridge inside is designed so water enters the canister on the outside of the cartridge then travels up through the resin from the bottom up. You can crack the seal on the canister while the system is running and bleed the air but it will come back. Doesn't hurt anything so I don't worry about it.

 

[-Logzor]

You are confusing the canister with the cartridge. The canister is the opaque or clear housing with a lid that unscrews and holds the cartridge which the resin is packed in. I replace the cartridge but reuse the canister.
The air in the canister does not matter. The cartridge inside is designed so water enters the canister on the outside of the cartridge then travels up through the resin from the bottom up. You can crack the seal on the canister while the system is running and bleed the air but it will come back. Doesn't hurt anything so I don't worry about it.

So in my case, I re-use the cartridge since I'm packing my own DI resin. Do you throw away the entire cartridge and resin every time?

 

[AZDesertRat]

Yes if you are using bulk resin or refills you reuse the cartridge. In my case Spectrapure does not sell MaxCap or SilicaBuster resin in bulk or refills due to the way it is blended and packed in stratified layers to take advantage of internal pH and other changes within the resin bed so I replace the cartridge and toss the old one or give them to someone who packs their own. I found it many times cheaper and more environmental friendly to do it this way since I get over a year on the MaxCap and 3 years on the SilicaBuster so not much gets thrown away.

 

[-Logzor]

What is the difference between MaxCap and SilicaBuster and why do you run both? Is there a particular issue with your water that you chose these resins?

Given the issues I just had with my DI resin, I'm looking at going the same route you are. I basically wasted two DI refills, even though I got 99% of the resin packed inside.

 

[AZDesertRat]

Go to Spectrapures website and look in their DI section. They explain the differences there.
If I remember right, they had a good explanation in their sponsors forum on Reef Central too.
Both resins are very different from anything else I have ever tried before and save me a ton of money.

 

[-Logzor]

I'll definitely research them, do you deal with chloramines in your water?

 

[AZDesertRat]

Phoenix does not use chloramination only free chlorine. Chloraimnes are not an issue for Spectrapure products though, any single 1 micron or smaller extruded carbon block is more than sufficient for the removal of the chlorine portion of chloramines and breaking the bond with the ammonia which is partially removed by the RO and polished off by the DI. The SilicaBuster DI is designed to take care of all forms of ammonia so doesn't even break a sweat.

 

[bozo]

I also don't fall for the water saver bunk with dual membranes, it's not that easy. Think about it for a minute, you are sending the concentrated waste from the first membrane into the second so it is even more important you keep the waste ratio at 4:1 for the membranes to last. Unfortunately some vendors have a lot to learn. Notice none of the other vendors, many who have been around for 25 years or more, promote dual membranes as a water saver? That should be a red flag in my book. It doesn't work line that, not for long anyway.

Are you sure that it doesn't work?

I'm thinking about doing it since I have extra parts laying around.

 

[AZDesertRat]

Yep, I'm sure. I have been doing this a long long time and know many vendors who have been in it for 25-30 years and longer who have much data to back it up. Talk to vendors who have been around for decades and get their take on it. If it really was that easy they would all have been doing it many years ago but that is not the case. Membranes must stay well flushed to work and to last, it has always been that way and nothing has magically changed in the last couple years. Research.

 

[-Logzor]

Yep, I'm sure. I have been doing this a long long time and know many vendors who have been in it for 25-30 years and longer who have much data to back it up. Talk to vendors who have been around for decades and get their take on it. If it really was that easy they would all have been doing it many years ago but that is not the case. Membranes must stay well flushed to work and to last, it has always been that way and nothing has magically changed in the last couple years. Research.

I'm thinking of removing mine, I have the dual membrane setup and it essentially forces a lower waste ratio and fries your DI resin faster. I do get more water in a shorter period of time, but at a cost.

 

[AZDesertRat]

Dual membranes will get you more GPD, providing you have a minimum of 65 psi available, you are using soft or softened water, your tap TDS isn't too high to begin with and you keep the waste ratio up where the manufacturers recommend it be. You will get a reasonable service life out of both membranes in this way. If any of all of the above are not true then you are asking for trouble or at a minimum a much higher cost of ownership since you will be replacing both DI resins and memebranes more frequently. If cost of operation isn't an issue to you then go for it, but it will cost you. Dual membranes are not water savers, they are a way to increase production. I have found adding a booster pump at 95-100 psi was a much better option that the dual membrane system I used to own. By increasing the pressure I increased the GPD of a 75 GPD membrane up to 150 GPD but the real cool thing is the rejection rate or removal efficiency goes way up so the 98% rejection rate membrane is now 99.43% rejection rate. A TDS of 560 going in comes out of the membrane at 2 TDS! With the dual membrane system that was more like 13-15 TDS so DI didn't last 1/4 as long or less. One membrane and a couple DI replacements was about he same $$ as an Aquatec 8800 booster pump.

I also tried a single 150 GPD membrane but found they are not as efficient as a 75. Spectrapure tried selling them for a short few months but they could not get enough to pass their quality control checks so they discontinued them. I sold mine.

 

[Triggreef]

Dual membranes will get you more GPD, providing you have a minimum of 65 psi available, you are using soft or softened water, your tap TDS isn't too high to begin with and you keep the waste ratio up where the manufacturers recommend it be. You will get a reasonable service life out of both membranes in this way. If any of all of the above are not true then you are asking for trouble or at a minimum a much higher cost of ownership since you will be replacing both DI resins and memebranes more frequently. If cost of operation isn't an issue to you then go for it, but it will cost you. Dual membranes are not water savers, they are a way to increase production. I have found adding a booster pump at 95-100 psi was a much better option that the dual membrane system I used to own. By increasing the pressure I increased the GPD of a 75 GPD membrane up to 150 GPD but the real cool thing is the rejection rate or removal efficiency goes way up so the 98% rejection rate membrane is now 99.43% rejection rate. A TDS of 560 going in comes out of the membrane at 2 TDS! With the dual membrane system that was more like 13-15 TDS so DI didn't last 1/4 as long or less. One membrane and a couple DI replacements was about he same $$ as an Aquatec 8800 booster pump.

I also tried a single 150 GPD membrane but found they are not as efficient as a 75. Spectrapure tried selling them for a short few months but they could not get enough to pass their quality control checks so they discontinued them. I sold mine.

I have a question for you on this dual membrane. I have some spare ro parts and was going to revamp my system a little bit. I have well water so I'm not worried about using more water to get more water. That said my plan for a dual membrane was first off to go through 2 sediments, then 2 carbon blocks. From there I was going to "Y" and feed 2 separate membranes, then "Y" the output (good water) from both of those back into 2 di resin cartridges.

I have a heavy zinc and copper in my water. TDS enters only at about 96 to 113 (2 seperate locations) in the house. With all new stuff I usually get 0 TDS but not for long, within months I get 1 to 2 TDS on the output. On this particular unit I have a helper pump and get about 110 psi with that. This unit runs a 60 gpd membrane and I was thinking of adding a 90 gpd membrane for the second one. Also my water is softened going in as I have a whole house softener since the water smells pretty bad without it.

Also my hope with all this is to be able to offset the replacements like change one sediment filter every 3 months, one carbon cartridge every 6 months etc etc.

 

[AZDesertRat]

More filters is not better, fewer, higher quality filters is better and more efficient.
What are you trying to accomplish? A single 75-90 gpd membrane at 110 psi will deliver well over 150 gpd and at a great rejection rate. If you have short DI life you either have an inefficient RO membrane or co2 in your water or both I would think. With incoming TDS that low you should get great DI life if you don't have co2 issues.
If you know your tap alkalinity and pH you can calculate your co2.

 

[Triggreef]

Ok I'll check that. I just changed my di and sediment like 3 weeks ago. It was getting 2 tds when I changed it, 0 after. Now it's already back to 2tds again.

I prolly made 300g in that time frame