chloramine question

[labragg1]

One quick question since you guys really seem to know your stuff. :)

If my city treats the water with chloramine and I don't have the Cat GAC stage that you recomended recently--will that cause premature exhaustion of my membrane and DI?

What ill effects do chloramines cause in relation to reef tanks?

I was just curious as I was thinking that this may be the root cause of the problem I have been having with my RO/DI unit doing great for a short time and then the TDS going back up through the roof.

I'm getting ready to order two of these Cat GAC stages for me and my friend's rodi unit. I'm also going to order a whole new round of cartridges and new membranes just to make sure everything is fresh.

I was just curious if this chloramine issue could be the cause of all my troubles.

Thanks

[BuckeyeFS]

Hopefully you have a high quality carbon block and high residence time/slow flow so that your single block may do ok (or it may not). If chloramines reach your membrane, a large percentage of it will likely be rejected. This is not the case in tap water with a pH over 7 where most of the chloramine will be monochloramine, and more of this will make it through the membrane. Dichloramine (the more common form at pH 4 to 7) would be rejected to a greater extent.

Chloramine has been shown to have toxicity in tests with fish, and a variety of other marine organisisms. This is summarized nicely in an article nby Randy Holmes Farley: Chloramine and the Reef Aquarium.

I'd have to hear more about your RODI systems to troubleshoot them further.

Sounds like you are on the right track in getting the cat GAC stages installed (after the sediment filter and before the carbon block).

Typically folks will get an add-on housing and install it before their system. They move their sediment filter into the new housing, and place the cat GAC into the housing that previously held the sediment filter.

Russ