Chloramine - check your water source!

[Myka]

I just found out that Saskatoon uses chloramine. I don't have chloramine filters in my RO/DI unit. This makes me wonder about some of the issues I've had with my reef tanks...

For those that don't know, chloramine is a chemical used by water treatment facilities. Some facilities choose to use chloramine as opposed to chlorine. In order to remove chloramine you have to break the bind of the chlorine and ammonia, then both need to be removed. Chloramine will not off-gas like chlorine will so adding an airstone to a bucket of water will not remove it. Typical carbon also will not remove chloramine.

If your water source contains chloramine you need chloramine-specific filters in your RO/DI unit before the RO membrane. Chloramine should damage the RO membrane (and irritate/harm the reef inhabitants), although my RO membrane is 18 months old now and I don't have any issues with it.

I can't wait to get the chloramine-specific filters in from BRS and do a big waterchange!

Please either send an email in to your water works division or check your local city website, you should double check. Thanks to one of our local reefers who tipped me off on this!

EDIT: Please check out Buckeye Field Supply's post on Page 5, post #43 for a professional answer to chloramines. Thanks Russ!

[Casey8]

Why don't you just use Prime to remove it ?

[Nano]

I use ro, but I get it from the water fill station, so its no deionized, I do still use prime though as our local water is treated with chloramine as well, luckily the RO has the extra membranes to remove chloramine. We switched to ro for drinking to as I found out our water has mercury in it too! its at a "safe" level, but whats safe?

[marie]

Canadian tire sells RO filters for chloramine

[fencer]

http://reefkeeping.com/issues/2003-11/rhf/feature/

[mark]

reminds me, time to change my pre-filters.

[Myka]

For those suggesting Prime, it is kinda difficult to get Prime into the water before the water goes through the RO/DI unit. After reading the article that fencer posted it sounds like monochloramine (the most common of three different chloramines) goes through the RO membrane not damaging it, but still getting to the tank. In which case adding Prime to the RO/DI product water could be a decent alternative.

Other references suggest that with a typical RO/DI unit the carbon block will convert the chloramine to chlorine and ammonia. The carbon will then convert that chlorine to chloride, which the RO will remove. The ammonia will make it through the RO where the DI will remove it. This would explain why I seem to burn through DI resin faster than what the TDS going to it suggest. There seems to be rather a bit of confusion on the subject! Several references suggest that catalytic carbon is required to break the bond of ammonia and chlorine. Hmmm...

I'm going to order a test kit. I wanted a chlorine kit anyway.

Originally Posted by fencer

http://reefkeeping.com/issues/2003-11/rhf/feature/

This is a really old article, but lots of very interesting information! Thanks for posting! I'm going to see if I can find something more recent.

[fishytime]

this may provide some insight as to why it seems that truly beautiful full blown SPS tanks seem to be zone specific......anyone else ever notice that or is it just me?

[Myka]

Yeah, I have been noticing that lately Doug.

Ok, I found this written in 2009. This written by Charles Metsis, President of SpectraPure. I bolded some interesting and/or important points.

Originally Posted by SpectraPure

More detailed explanation on Chloramines, membranes and carbon filters:

In order to understand the mechanism of chloramine removal, a little background information on the chemistry of chloramines is necessary. Chloramines are formed by the reaction of ammonia and chlorine gas. Chloramines can exist as three chemical species: monochloramine (the predominant species found in tap water), dichloramines and trichloramines. The chloramine species depends upon the pH of the water and the ratios of chlorine to ammonia. At tap water pH levels of 7 to 8.5, the formation of monochloramines is favored. Of the three species, monochloramine is the most stable and difficult to remove, as well as the most damaging to aquatic life.

A “ppm-hour” is defined as the exposure of 1 ppm chlorine/chloramine water for 1 hour. Film-Tec quotes 300,000 ppm-hours (six years at 1 ppm) of chloramine resistance for their TFC polyamide (PA) membrane material, but only 200 to 1000 ppm-hours of free chlorine resistance. This indicates that chloramines will not damage Film-Tec membranes, while free chlorine levels must be held below 0.1 ppm to prevent oxidation damage. The easiest test for chloramine is with a Total Chlorine Test Kit (SpectraPure Part # TK-CL-10). The TK-CL-10 tests for a combination of free chlorine and chloramines. A sample of the wastewater stream from the RO membrane should show no signs of chlorine.

The most important purpose of a sediment filter is to protect the downstream carbon block filters from plugging with sediment. A properly designed sediment filter will have a micron rating smaller or equal to the closest downstream filter element. It will have a gradient density structure such that the outer layers capture the larger particles and the inner layers capture the finer particles. This will maintain a large dirt holding capacity and prevent the finer particles from plugging downstream carbon filters. Using a 5 micron carbon block followed by a 0.5 micron carbon block, maximum chlorine and volatile chemical removal can be achieved without premature filter failure. If a sediment filter is used that passes particles larger than the next downstream filter, that filter will plug, blinding off the active carbon surfaces, reducing its ability to remove chlorine and organic chemicals.

Trade-offs exist in almost any circumstance and carbon filtration is no exception. The smaller the micron rating, the better the removal capacity due to greater surface area. Carbon block filters made with bituminous carbon are more effective than coconut shell carbon filters for removal of monochloramine. On the other hand, in water supplies with chlorine only, the coconut shell carbon may have higher capacities for the removal of free chlorine and low molecular weight volatile organic compounds such as trihalomethanes (chloroform). Multi-carbon block pre-filtration is not always necessary, especially in smaller flow rate systems when adequate pre-filtration and sub-micron carbon block filters are used. Activated carbon will break the chloramine bond and remove the chlorine component leaving free ammonia (NH3+). RO membranes are transparent to dissolved gases that will pass freely through the membrane concentrating in the RO product water.

Generally, reverse osmosis water is slightly acidic, due to the higher ratio of free CO2 to bicarbonate alkalinity. The exception to this rule is the presence of high pH “soda-lime softening” used by some municipalities. Free CO2 dissolved in water forms carbonic acid that lowers the pH to the range of 5 to 6 pH. In low pH RO product water, the ammonia is converted to the ionized ammonium ion NH4+. Downstream de-ionizing resins can then easily remove this charged species. It is cationic and removed by strong acid cation resins (in the hydrogen form) in either mixed bed or separate bed systems. Aquarists can be certain that when salt is properly added to RO or RO/DI water, the expected salinity and pH will be realized.

[MarkoD]

Anyone know if north Edmonton uses chloramine?

And I think of you use prime for chloramine it'll just turn it into ammonia. Just don't know what the concentration is