jrp1588
New member
I could keep it down in the basement, but then I'd have to lug a 5 gallon bucket of water upstairs. Is there any problem with just disconnecting the DI part for a couple minutes?
Chloramine
- Thread starter jrp1588
- Start date
I could keep it down in the basement, but then I'd have to lug a 5 gallon bucket of water upstairs. Is there any problem with just disconnecting the DI part for a couple minutes?
Disconnecting the DI the whole time it is not in use will prevent creep, but don't leave it open to the air or CO2 will get in.
The main problem is the ro membrane itself, and salt creeping across it to the other side, probably not so much the salt actually entering the di between uses, so never mind, disconnecting it likely is not very useful. 
aleonn
New member
Thats a good question. It had a chlorine or chloramine smell to me, but then again, I'm not sure what ammonia smells like. The next time I top off my ATO, I'll be sure to measure for ammonia.
You can also measure chloramine and chlorine with an inexpensive total chlorine kit.
Rybren
Well-known member
My understanding is that most of the Thin Film Composite RO Membranes that we use are suceptible to damage from chlorine. (can be damaged by as little as 0.1 ppm according to the Alberta Government website )
One of the purported advantages of using the Chloramine-specific carbon blocks is that it removes more of the chlorine after the ammonia-chlorine bond is broken, thus extending the life of the membrane. Is this more marketing hype or is there any truth to the theory?
One of the purported advantages of using the Chloramine-specific carbon blocks is that it removes more of the chlorine after the ammonia-chlorine bond is broken, thus extending the life of the membrane. Is this more marketing hype or is there any truth to the theory?
That's isn't my understanding of the way carbon breaks down chloramine. It does not remove ammonia and leave chlorine as a first step.
This is from my chloramine article:
Removing Chloramine From Water: Activated Carbon
Another method for removing chloramine from water is with activated carbon (as is contained in most RO/DI systems). In a two step process, the carbon catalytically breaks the chloramine down into ammonia, chloride, and nitrogen gas
C + NH2Cl + H2O --> C-O + NH3 + Cl- + H+
C-O + 2NH2Cl --> C + N2 + 2Cl- + 2H+ + H2O
where C stands for the activated carbon, and C-O stands for oxidized activated carbon. In this case, as was found for thiosulfate, the product includes ammonia, which is not bound significantly by activated carbon. Consequently, treatment of water with activated carbon will need to be followed up by some method of eliminating the ammonia.
In the case of a reverse osmosis/deionizing system (where carbon is usually part of the prefiltration prior to the RO membrane), the ammonia is partially removed by the reverse osmosis system. The extent of removal by the RO membrane depends on pH. At pH 7.5 or lower, reverse osmosis will remove ammonia from 1.4 ppm-Cl monochloramine to less than 0.1 ppm ammonia. The DI resin then removes any residual ammonia to levels unimportant to an aquarist.
This is from my chloramine article:
Removing Chloramine From Water: Activated Carbon
Another method for removing chloramine from water is with activated carbon (as is contained in most RO/DI systems). In a two step process, the carbon catalytically breaks the chloramine down into ammonia, chloride, and nitrogen gas
C + NH2Cl + H2O --> C-O + NH3 + Cl- + H+
C-O + 2NH2Cl --> C + N2 + 2Cl- + 2H+ + H2O
where C stands for the activated carbon, and C-O stands for oxidized activated carbon. In this case, as was found for thiosulfate, the product includes ammonia, which is not bound significantly by activated carbon. Consequently, treatment of water with activated carbon will need to be followed up by some method of eliminating the ammonia.
In the case of a reverse osmosis/deionizing system (where carbon is usually part of the prefiltration prior to the RO membrane), the ammonia is partially removed by the reverse osmosis system. The extent of removal by the RO membrane depends on pH. At pH 7.5 or lower, reverse osmosis will remove ammonia from 1.4 ppm-Cl monochloramine to less than 0.1 ppm ammonia. The DI resin then removes any residual ammonia to levels unimportant to an aquarist.
FWIW, the old article is no longer on the web, but here is an archived version of the GE article which supplied the above mechanism and discusses removing chloramine with carbon:
http://web.archive.org/web/20030816123638/http://www.gewater.com/library/tp/813_Chloramines_.jsp
http://web.archive.org/web/20030816123638/http://www.gewater.com/library/tp/813_Chloramines_.jsp
If you mean to just let the first few minutes of ro water go down the drain then that should help save resin and lessen any tds creep.I have no idea how much it would help,though, or how long you would need to run it . Long runs of several hours are better than short runs.
Some also suggest plumbing in a by pass via a tee in the wastewater line with a ball valve to by pass the flow restrictor and enable periodic flushing of the membrane surface .These are sold as membrane flushing kits. Obviusly the flushed water should be put down the drain.
Some also suggest plumbing in a by pass via a tee in the wastewater line with a ball valve to by pass the flow restrictor and enable periodic flushing of the membrane surface .These are sold as membrane flushing kits. Obviusly the flushed water should be put down the drain.
Chloride (Cl-) is a prime ingredient in any water source (including seawater where it is the main ion present), and won't hurt any membrane nor will it bind to carbon.
You're welcome.
Happy reefing.
Happy reefing.
My area switched to chloramine like many cities recently.
I found out after I was concerned why DI filter was exhausting faster. I researched carbon options and just went with a 20 X2.5" carbon canister instead of a 10" canister to increase dwell time.
The manufactures of catalytic carbon will harp on dwell time as a key factor also needed in promoting the preferred reaction of chloramine to N2 and chloride. I chose not to use catalytic carbon since the extruded block products are cheaper and appeared to have more surface area. I can rotate these every 3-4 months much cheaper.
I now use this sequence on a 75 gpd typical system
prefilter
20" carbon block
RO membrane
DI canister
DI canister polisher - since I had it anyway
I found out after I was concerned why DI filter was exhausting faster. I researched carbon options and just went with a 20 X2.5" carbon canister instead of a 10" canister to increase dwell time.
The manufactures of catalytic carbon will harp on dwell time as a key factor also needed in promoting the preferred reaction of chloramine to N2 and chloride. I chose not to use catalytic carbon since the extruded block products are cheaper and appeared to have more surface area. I can rotate these every 3-4 months much cheaper.
I now use this sequence on a 75 gpd typical system
prefilter
20" carbon block
RO membrane
DI canister
DI canister polisher - since I had it anyway
Snarkys
.Registered Member
A customer asked me to chime in on this thread. This link is a helpful read for those of you looking to learn more about chloramines. http://www.carbonresources.com/pdf/0906Potwora.pdf
We find it isn't chloramine breakthrough that is the issue in most cases it is the resulting ammonia from the reaction with the carbon. Randy posted the two types of reactions that can happen a few posts above, they can be found in the above link as well. Basically one results in the creation of ammonia and the other nitrogen. As aquarium owners we would obviously prefer the second reaction.
Standard activated carbon is capable of producing the desired nitrogen reaction but requires pretty long contact times that aren't typical with your standard 75 GPD ro system. Catalytic activated carbon or surface activated carbon is much more likely to produce the nitrogen reaction. The manufactures don't explicitly state how they have modified the surface of the carbon but I assume they are increasing the volume of oxidized carbon sites to help promote the desired reaction. C-O + 2NH2Cl --> C + N2 + 2Cl- + 2H+ + H2O. As to the ability of the RO membrane and DI resin to remove ammonia. It's possible this can be effective but these two options are not the ideal water treatment options for ammonia, treating properly it before these stages is preferred.
The catalytic carbon granules are a bit messy compared to a carbon block and the specialized chloramine carbon blocks are more expensive. In the end it is an individual cost/benefit analysis for everyone. Personally, I think the $10-20 extra every few months is worth the peace of mind.
We find it isn't chloramine breakthrough that is the issue in most cases it is the resulting ammonia from the reaction with the carbon. Randy posted the two types of reactions that can happen a few posts above, they can be found in the above link as well. Basically one results in the creation of ammonia and the other nitrogen. As aquarium owners we would obviously prefer the second reaction.
Standard activated carbon is capable of producing the desired nitrogen reaction but requires pretty long contact times that aren't typical with your standard 75 GPD ro system. Catalytic activated carbon or surface activated carbon is much more likely to produce the nitrogen reaction. The manufactures don't explicitly state how they have modified the surface of the carbon but I assume they are increasing the volume of oxidized carbon sites to help promote the desired reaction. C-O + 2NH2Cl --> C + N2 + 2Cl- + 2H+ + H2O. As to the ability of the RO membrane and DI resin to remove ammonia. It's possible this can be effective but these two options are not the ideal water treatment options for ammonia, treating properly it before these stages is preferred.
The catalytic carbon granules are a bit messy compared to a carbon block and the specialized chloramine carbon blocks are more expensive. In the end it is an individual cost/benefit analysis for everyone. Personally, I think the $10-20 extra every few months is worth the peace of mind.
This article (already quoted in part )covers chloramine in detail:
http://reefkeeping.com/issues/2003-11/rhf/feature/index.php
RO membranes remove ammonia fairly well, and DI should get the rest. I never bothered with a special carbon filter for chloramine, and never had any problems.
If I were using a system for treating drinking water without RO or DI, I'd consider looking at a catalytic filter.
)covers chloramine in detail:http://reefkeeping.com/issues/2003-11/rhf/feature/index.php
RO membranes remove ammonia fairly well, and DI should get the rest. I never bothered with a special carbon filter for chloramine, and never had any problems.
If I were using a system for treating drinking water without RO or DI, I'd consider looking at a catalytic filter.
Randy's article is well written and cited above, but does not explain contact time needed in pressurized systems to effect the preferred reaction to nitrogen. It also assumes your willing to accept residual ammonia in your RODI system, to burn membranes and resins. Retail replacement of cartridges would be expensive long term, and may prove more expensive than getting correct equipment. Aging water in aerated system is best answer maybe.
Based on 75 gpd system with a realistic 1:5 product ration, ~0.25 gpm feeds filter. That means 10" X 2.5" canister is ~1/4 gallon with 1 minute of contact time, where as two in series is 2 minutes etc. 10" X 5" canister is ~0.8 gallon with ~2.5 minutes of contact time in canister. 20" X 2.5" canister is ~0.5 gallons or ~1.5 minutes of contact tome
20" X 5" canister is ~1.7 gallons or 5.6 minutes of contact time. From what little I have read 10 minutes is ideal. but 5-6 minutes of contact time should work to effect preferred removal reaction. I am not aware of larger canisters. I did find the jumbo canister for about 80 usd.
On a five stage system you would have two canisters for DI resin. Spectrapure makes a high capacity resin that does not color change in first chamber. Second chamber does color change. So I tried to demonstrate complete removal of chloramine is possible with home systems. It also shows 10" canisters in series do not gain much effectiveness, unless you simply want to have them take brunt of organics out of water first.
I also do not work for hobbyist suppliers!
http://www.calgoncarbon.com/documents/CatalyticActivatedCarbonOffersBreakthroughforDialysis.pdf
Based on 75 gpd system with a realistic 1:5 product ration, ~0.25 gpm feeds filter. That means 10" X 2.5" canister is ~1/4 gallon with 1 minute of contact time, where as two in series is 2 minutes etc. 10" X 5" canister is ~0.8 gallon with ~2.5 minutes of contact time in canister. 20" X 2.5" canister is ~0.5 gallons or ~1.5 minutes of contact tome
20" X 5" canister is ~1.7 gallons or 5.6 minutes of contact time. From what little I have read 10 minutes is ideal. but 5-6 minutes of contact time should work to effect preferred removal reaction. I am not aware of larger canisters. I did find the jumbo canister for about 80 usd.
On a five stage system you would have two canisters for DI resin. Spectrapure makes a high capacity resin that does not color change in first chamber. Second chamber does color change. So I tried to demonstrate complete removal of chloramine is possible with home systems. It also shows 10" canisters in series do not gain much effectiveness, unless you simply want to have them take brunt of organics out of water first.
I also do not work for hobbyist suppliers!
http://www.calgoncarbon.com/documents/CatalyticActivatedCarbonOffersBreakthroughforDialysis.pdf
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