How efficient is your RODI

[DDenny]

I have a 5 stage RODI unIt from Koolermax and it works great for me. Just changed out the resin thought it was a little soon as I have had it running since late April. My tap water is at 993ppm the filters before DI drops it to 43 and after DI zero. I only make about 3g weekly for water change top-off and other items around the house (wife’s defusers). So this morning I changed the DI as I was start to get to 1-2ppm TDS after the DI. I packed in as much as I could fit in the resin chamber. Hopefully that is what I was supposed to do correct me of that is wrong.
How often do you change your resin out and your filters for the RODI unit?

 

[KStatefan]

DI resin will not last long when receiving 43 tds water. If you are only making 3 gallons at a time you would also be getting a lot of tds creep unless you have a DI bypass installed to send the first couple gallons down the drain.

 

[T-J]

My city water fluctuates between about 450-500 TDS. After my RO membrane, it's down to 3-4 TDS. 0 after the DI. I just changed my sediment and two carbon blocks after about 6 months. I make water pretty regularly for my ATO on my 40g cube and my 120g tank.

 

[ReefPiracy]

I don't use DI resin since it burns up so fast. 43 is pretty high I run 5/6 no issues.

 

[T-J]

I don't use DI resin since it burns up so fast. 43 is pretty high I run 5/6 no issues.

My DI resin lasts about 3-4 months. I don't think that's terribly fast. Especially when you buy it in bulk and refill your own.

 

[KStatefan]

I change the sediment filter annually
I change the first carbon filter at 2000 gallons used
I change the second carbon filter at 4000 gallons used
I change the membrane when rejection is less then 97%
I change the first DI when the output is 50% of the input
I change the second DI when output is not zero.

I think I am going to add two more stages to my DI. Before I added my degassing chamber I had to replace first di after 50 gallons.

 

[Quietman]

I have the KoolerMax AR-122. It's served me very well. You're dropping close to 95% which is what mine does. That high of input and you're going to burn resin.

As far as those DI filters on top - the horizontal ones. My resin only lasted a hundred gallons and channeled badly. The next day I ordered the 3 stage resin (overkill a tad but I don't regret it at all) because the mixed bed resin was depleted really quickly. I have 400 ish ppm input so about 15 ppm to the DI resin.

That three stage helped quite a bit...I burn then anion bed quickest but it lasts several hundred gallons. The mixed bed has been over a year with an inch or so gone now and the cation bed looks like new.

Also get a bypass for that system so you can flush easy. The RO filter will last longer.

 

[Quietman]

Oh one last thing that happened at 2 year point. The pressure gauge stopped working. Only read 1/2 of pressure (had me troubleshooting and replacing/reseating filters until I figured that out when I got my own pressure gauge).

 

[Oregon Grown Reef]

I don't use DI resin since it burns up so fast. 43 is pretty high I run 5/6 no issues.

This isn't good advice. It might work for you, which is lucky, but if even a small percent of that is copper you're tank is done for.

OP, why are you using runoff water to make rodi? Of course I kid, but that really sucks. Packing in the media as tight as possible is recommended so there isn't any channeling. The problem here is that you're going to run out of di resin very quickly no matter what you do. Someone above suggested flushing the ro membrane, which will help a little since you make such small batches. . A simple 3 way valve will allow you to do that.

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You direct the water after the ro membrane to flush down the drain instead of running in the di. As water sits in the filter, the tds starts to rise, so you get an initial flood of tds going into the di resin until it's been running for a bit. It only takes a minute to do.

To answer your last question, I change out my filters every year or so, but just because I'd rather change it out before the tds rises.

 

[Tamberav]

I have a 5 stage RODI unIt from Koolermax and it works great for me. Just changed out the resin thought it was a little soon as I have had it running since late April. My tap water is at 993ppm the filters before DI drops it to 43 and after DI zero. I only make about 3g weekly for water change top-off and other items around the house (wife’s defusers). So this morning I changed the DI as I was start to get to 1-2ppm TDS after the DI. I packed in as much as I could fit in the resin chamber. Hopefully that is what I was supposed to do correct me of that is wrong.
How often do you change your resin out and your filters for the RODI unit?

holy crap 993. It sounds like you maybe need two membranes and more stages on the RO part as 43 is high after the RO stage still.

My MAXcap super DI lasts me two years but my TDS in is 135 and 0-1 after RO. I don't like the color changing crap you have to pack yourself tbh.

 

[guylaga]

BRS 4 stage with dual DI Canisters.

Sediment filter + 10micron and 1micron carbon blocks changed every six months.
RO Membrane changed annually.

I do not know TDS of my tap water, but out of the RO I get 3-4 TDS. I manually flush the first two minutes and another two minutes or so after making a batch of water. Always 0 TDS out of the DI unit.

I use the DI color change resin from BRS, I will let the fistcanister go all brown, by that point the 2nd is brown about 1/3 the way up to the top. Then swap canisters so the 2nd is now the first and refill the first which becomes the 2nd.

I rather waste a bit of DI and get 0 TDS than let somthing creep by that causes a die off in the tank.

 

[RobB'z Reef]

I change the sediment filter annually
I change the first carbon filter at 2000 gallons used
I change the second carbon filter at 4000 gallons used
I change the membrane when rejection is less then 97%
I change the first DI when the output is 50% of the input
I change the second DI when output is not zero.

I think I am going to add two more stages to my DI. Before I added my degassing chamber I had to replace first di after 50 gallons.

What are you using for a degassing chamber?

 

[anthonygf]

I change the sediment filter annually
I change the first carbon filter at 2000 gallons used
I change the second carbon filter at 4000 gallons used
I change the membrane when rejection is less then 97%
I change the first DI when the output is 50% of the input
I change the second DI when output is not zero.

I think I am going to add two more stages to my DI. Before I added my degassing chamber I had to replace first di after 50 gallons.

How do you determine what the rejection rate is? Just curious.

 

[anthonygf]

I have the KoolerMax AR-122. It's served me very well. You're dropping close to 95% which is what mine does. That high of input and you're going to burn resin.

As far as those DI filters on top - the horizontal ones. My resin only lasted a hundred gallons and channeled badly. The next day I ordered the 3 stage resin (overkill a tad but I don't regret it at all) because the mixed bed resin was depleted really quickly. I have 400 ish ppm input so about 15 ppm to the DI resin.

That three stage helped quite a bit...I burn then anion bed quickest but it lasts several hundred gallons. The mixed bed has been over a year with an inch or so gone now and the cation bed looks like new.

Also get a bypass for that system so you can flush easy. The RO filter will last longer.

Hey Quietman. Think your RO membrane is going bad? My TDS defore is 576 and after down to 7ppm, I also have a dual RO membrane setup.

 

[Jekyl]

I have a 5 stage RODI unIt from Koolermax and it works great for me. Just changed out the resin thought it was a little soon as I have had it running since late April. My tap water is at 993ppm the filters before DI drops it to 43 and after DI zero. I only make about 3g weekly for water change top-off and other items around the house (wife’s defusers). So this morning I changed the DI as I was start to get to 1-2ppm TDS after the DI. I packed in as much as I could fit in the resin chamber. Hopefully that is what I was supposed to do correct me of that is wrong.
How often do you change your resin out and your filters for the RODI unit?

Filters maybe once a year. DI resin I get about 200gal give or take.

 

[KStatefan]

What are you using for a degassing chamber?

A piece of 4" pvc

 

[KStatefan]

How do you determine what the rejection rate is? Just curious.

(TDS in - TDS out) / TDS in

 

[anthonygf]

I have a 5 stage RODI unIt from Koolermax and it works great for me. Just changed out the resin thought it was a little soon as I have had it running since late April. My tap water is at 993ppm the filters before DI drops it to 43 and after DI zero. I only make about 3g weekly for water change top-off and other items around the house (wife’s defusers). So this morning I changed the DI as I was start to get to 1-2ppm TDS after the DI. I packed in as much as I could fit in the resin chamber. Hopefully that is what I was supposed to do correct me of that is wrong.
How often do you change your resin out and your filters for the RODI unit?

Hello DDenny. Sounds like you need a water softener. I have the same high TDS in my water and after softener is down to 576. After RO is 7ppm.

 

[anthonygf]

(TDS in - TDS out) / TDS in

Was getting confused a little, was thinking of the waste water to product water ratio. Thanks.

 

[Doug6952]

Bought a used ro unit about 20 years ago. No idea what brand it is. Came with a booster pump. I added a second membrane and plumbed it so the waste water from first membrane feeds the second membrane. Changed the membranes in January since I couldn't remember the last time I changed them and 1 of the housings started leaking. For sediment and carbon filters I get them from airwaterice.com and change them annually.

Tap water is about 40-50 ppm tds. Water comes out of ro at 0 tds. Just ordered a di canister to make sure I have pure water.
Waste water from ro is 200ppm tds.