Chloramines in Portland City water and RO/DI

[Cobalt]

Portland uses Chloramine in its water supply. I read Chloramine will not destroy an RO membrane but it will work your DI harder as monochorline will pass through the membrane. Does anyone here notice their DI life is less than than 12 months? Does anyone use the more expensive Chloramine reducing carbon block prefilters?

[Twitterbait]

i have a new system with 3 prefilters... they are not too expensive

[Cobalt]

i have a 5 stage too, one sediment and two carbon blocks. but do you have the expenive cloramine guzzler carbon blocks?

 

judging by the near 0 interest this threa has received, i'm guessing no one is concerned about cholramines (from their RO water at least)

[Sol]

monochloramine is a charged ion, so they'll get taken out by your DI. Yes, it'll use up your DI faster than having nothing at all in the water, but there's nothing "special" about it that will work the DI harder than any other ion the DI removes.

 

I think in terms of cost-effectiveness, using up the DI resin a tiny bit faster is much cheaper than investing in one of the special carbon chloramine remover prefilters. FWIW, I have the color changing DI, and change it out when it changes color--much less often than every 12 months, more like every 24-30. That's at an average of about 25 gallons a week, between top off and water changes.

 

I'm not sure if you're mainly worried about working the DI too hard, or about have chloramines in the produced water. Either is really a very low-probability issue, IMO.

 

Edit: I'm being tired and stupid, and am wrong. Monochloramine is not a charged ion, and will not be removed by DI. Carbon is neccesary to remove it (or alternatively, some reducing reaction). I guess the question, then, should be when the carbon reaches saturation point, and whether it's worthwhile to filter it. Personally, I'm of the "if it ain't broke, don't fix it", and am not seeing any signs of chlorine toxicity in any aquarist's tanks (that I know of), and so don't see a need.

 

-Sol