RODI-Chloramine

[bcarl77]

Hi All,

I run a BRS RODI system 150 gpd water saver 5 stage + DI with 2 Chloraguard carbon blocks. My city uses a lot of chloramines (3-5ppm, total chlorine consists of predominately chloramines). Since tank set-up I have noticed around every 2-3 months I start to see some issues with corals going south. Once I rotate out the carbon blocks, things seem to perk up. I estimate that in the 2-3 months I run about 1,000G of water through the RODI, which I think should be well under the useful life of the carbon blocks.

I have been testing the product water with the Hanna ULR Total Chlorine checker and I am getting a 0ppb reading. When I test the rejection water I am getting 55ppb of total chlorine, which is making me think the carbon blocks are letting a small amount through. Why is the product water reading zero when the output water is showing some chlorine still?

Would it be worth getting the chloramine monster to improve the rejection and reduce the breakthrough?

 

[FindinNemo]

It seems like the issue with your BRS RODI system is related to chloramine breakthrough. While carbon blocks do a good job of removing chlorine, they’re not as effective at breaking down chloramines, which are more persistent and harder to filter out. Since your city water contains 3-5 ppm of chloramines, after 2-3 months of use, your carbon blocks likely become saturated and can no longer keep up, allowing small amounts of chloramine to pass through into your product water.

The fact that you're getting a 0 ppb reading for chlorine in the product water but 55 ppb in the rejection water suggests that while the DI stage may be handling the remaining chloramines, the carbon blocks aren’t fully removing them. It’s possible the Hanna ULR Total Chlorine checker is just not sensitive enough to pick up low levels of chloramine in the product water, even though it's still there in trace amounts.


The Chloramine Monster uses KDF media, which is much more effective at breaking down chloramines compared to regular carbon blocks. By installing it before your RODI system, it will help reduce the chloramine load, allowing your carbon blocks to last longer and improving the overall water quality.

In the long run, I think investing in a Chloramine Monster is worth it. Since you’re seeing coral health issues possibly related to chloramine exposure, this could make a big difference. It will help ensure chloramines are removed before they get to your RODI, extend the life of your carbon blocks, and should lead to healthier corals overall.

Best of luck!

 

[bcarl77]

It seems like the issue with your BRS RODI system is related to chloramine breakthrough. While carbon blocks do a good job of removing chlorine, they’re not as effective at breaking down chloramines, which are more persistent and harder to filter out. Since your city water contains 3-5 ppm of chloramines, after 2-3 months of use, your carbon blocks likely become saturated and can no longer keep up, allowing small amounts of chloramine to pass through into your product water.

The fact that you're getting a 0 ppb reading for chlorine in the product water but 55 ppb in the rejection water suggests that while the DI stage may be handling the remaining chloramines, the carbon blocks aren’t fully removing them. It’s possible the Hanna ULR Total Chlorine checker is just not sensitive enough to pick up low levels of chloramine in the product water, even though it's still there in trace amounts.


The Chloramine Monster uses KDF media, which is much more effective at breaking down chloramines compared to regular carbon blocks. By installing it before your RODI system, it will help reduce the chloramine load, allowing your carbon blocks to last longer and improving the overall water quality.

In the long run, I think investing in a Chloramine Monster is worth it. Since you’re seeing coral health issues possibly related to chloramine exposure, this could make a big difference. It will help ensure chloramines are removed before they get to your RODI, extend the life of your carbon blocks, and should lead to healthier corals overall.

Best of luck!

Thanks this was really helpful, and along what my thoughts were as well. Just didn't know if my line of thought made sense. Do most people place a sediment filter prior to the Chloramine monster? Or could I run it after the 2 carbon blocks (not sure that set-up makes much sense)

Honestly, the thing will pay for itself if I skip 1 recession event.

 

[Randy Holmes-Farley Verified Community Expert]

For many people, myself included, normal carbon blocks adequately remove chloramine. Your source water is quite high and it may be an issue, but I would not assume it is without checking, as you have.

Both the ro membrane and the di will also serve to remove chloramine. But I’d replace the blocks with normal it special ones as soon as it rises in the waste water so that it doesn’t damage the membrane.

This has more:

Chloramine and the Reef Aquarium - Reefkeeping.com

 

[spsick]

I use 2 of the BRS universal carbon blocks in series. I have to change the first one every 2 months or I get blow through and I change the second one every 6 months for security. Same thing here we have a lot of chloramine.

I am making wayyy less water than you so you may need to change more frequently.

I’ve tested a number of carbon blocks and the BRS held up the best of the 10” x 2.5” size.

For my drinking water so use the Chloramine monster (Pentek CRFC-BB) and it lasts 6 months supplying all of the cold water to my kitchen faucet so I imagine it would benefit me to put one on my RODI unit as well…

 

[bcarl77]

For many people, myself included, normal carbon blocks adequately remove chloramine. Your source water is quite high and it may be an issue, but I would not assume it is without checking, as you have.

Both the ro membrane and the di will also serve to remove chloramine. But I’d replace the blocks with normal it special ones as soon as it rises in the waste water so that it doesn’t damage the membrane.

This has more:

Chloramine and the Reef Aquarium - Reefkeeping.com

Are you saying dont use a specialized carbon blocks? Or change the blocks when waste water chloramine rises?

 

[spsick]

Now if you really want to geek out and dial it in, get a Hach CN-70 and put a 2 way valve after each carbon block so you can flush them properly and test each one for chloramine blow through. Ask me how I know haha

 

[Randy Holmes-Farley Verified Community Expert]

Are you saying dont use a specialized carbon blocks? Or change the blocks when waste water chloramine rises?

I’m saying don’t use them just because manufacturers want you to use them. Use them if regular blocks are shown to be inadequate.

 

[bcarl77]

I’m saying don’t use them just because manufacturers want you to use them. Use them if regular blocks are shown to be inadequate.

I think thats what I am trying to determine. If the current configuration is fine and the coral response after changing is coincidental or given I am measuring some getting through in waste water they aren’t getting it all.

I also thought I read several places that the membrane and DI doesn’t remove it given there is no charge? Your article seems to indicate they can remove chloramine.

 

[bcarl77]

Now if you really want to geek out and dial it in, get a Hach CN-70 and put a 2 way valve after each carbon block so you can flush them properly and test each one for chloramine blow through. Ask me how I know haha

I would be interested to hear what led you to test and how tank responded. Sounds like we may have a similar situation…

 

[Randy Holmes-Farley Verified Community Expert]

I also thought I read several places that the membrane and DI doesn’t remove it given there is no charge? Your article seems to indicate they can remove chloramine.

Yes, they will to some extent. Not perfectly or even adequately on their own, however.

 

[bcarl77]

@Randy Holmes-Farley so are we thinking the current setup is likely adequate given no Total Chlorine in the product water?

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley so are we thinking the current setup is likely adequate given no Total Chlorine in the product water?

I cannot see the product water being a tank problem if you detect no total chlorine with a decent kit.

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley so are we thinking the current setup is likely adequate given no Total Chlorine in the product water?

I cannot see the product water being a tank problem if you detect no total chlorine with a decent kit.

 

[bcarl77]

Agree, Thanks Randy

 

[EeyoreIsMySpiritAnimal]

The Chloramine Monster uses KDF media, which is much more effective at breaking down chloramines compared to regular carbon blocks. By installing it before your RODI system, it will help reduce the chloramine load, allowing your carbon blocks to last longer and improving the overall water quality.

@FindinNemo , why do you advise this? You are essentially saying to add extra carbon  before the sediment filter and carbon that are already part of the RODI... Your answers to recent posts strongly suggest you are still regurgitating computer generated information; please stop trying to answer questions you have no idea about.

 

[bcarl77]

Quick update here. I checked the water coming out of the carbon blocks after running system for a few minutes. Got 22/27 ppb of total chlorine so there is some coming through blocks that are less than 1 month old

 

[spsick]

Quick update here. I checked the water coming out of the carbon blocks after running system for a few minutes. Got 22/27 ppb of total chlorine so there is some coming through blocks that are less than 1 month old

And those are Chloraguard you said? Dang. Try the BRS ones and if you’re still burning them up may be time to junk to that CRFC-BB yikes!

Is that at full blast? You may need to throttle flow a bit to mimic the lower speed it would go through with the back pressure of the membrane.

 

[bcarl77]

And those are Chloraguard you said? Dang. Try the BRS ones and if you’re still burning them up may be time to junk to that CRFC-BB yikes!

Is that at full blast? You may need to throttle flow a bit to mimic the lower speed it would go through with the back pressure of the membrane.

Yes, pushing about 60-65psi into membrane. No booster pump, we have great water pressure.

 

[Randy Holmes-Farley Verified Community Expert]

And the same kit reads zero on other water?