Thanks for the info. I do have an active carbon as the second stage.... So I should be safe. But during water change, I think I will still add prime from now on. Just incase.

its important to remember that that most household RO systems are just running a low micron prefilter and a ro membrane.

as BBLinks article stated activated carbon will pretty much get rid of all of the chloramine. Most of your aquarium grade RO/DI units use atleast one carbon stage as part of prefiltering.

i guess the question is how effecient is the carbon block at removing chloramines and when would it be exhausted. IS there a hobby grade kit we can purchase for chloramine testing?

To the best of my knowledge, RO systems rated for chloramine simply incorporate two carbon stages. I've only skimmed through the linked articles briefly, but my own system came with two carbon stages & was rated for chloramine removal because of that. When I found out Greater Vernon uses chlorine, I removed the activated carbon stage & added another poly pre filter in its place. So now I have a 5 micron poly, a 1 micron poly, 0.5 micron carbon block 'chlorine guzzler', RO membrane & finally DI. Been running for close to 3 years, DI is still good, membrane still good. Only thing I've ever replaced is the first stage 5 micron poly. Tap water TDS is 210-220.

Yes, Edmonton uses chloramine. If took this quote off of Epcor's Edmonton water treatment website. (4) Chlorine, (Total Residual)
In EPCOR's distribution system, the total residual chlorine is composed entirely of chloramine. Chloramine is a disinfectant that results when chlorine is combined with ammonia. It is a much weaker disinfectant than free chlorine but it stays in water longer, is more stable in distribution systems, and can more effectively penetrate any film or deposit on a pipe to kill bacteria. Our approval sets limits of 0.5 - 2.5 mg/L for drinking water. EPCOR's treated water contains an average of 2.19 mg/L.

hmmmm ..... wont the RO stage or DI resin remove it?

from Spectrapures site (in reference to their carbon blocks)

http://www.spectrapure.com/SYSTEM_BREAKDOWN.htm

CARBON BLOCK PRE-FILTER (2nd Stage Filter)
A Carbon Filter also has specific ratings that range from 5, 1 and 0.5. Each rating determines how much chlorine is removed in gallons of water. The 5 micron can remove chlorine for up to 6,000 gal, the1 micron for up to 9,000 and the 0.5 micron 20,000. This filter is in the 2nd stage. It removes chlorine, organics, heavy metals, trihalomethanes, pesticides and many other chemical pollutants. It will also break-up chloramines, which is chlorine bonded with ammonia ( removes the chlorine and leaves the ammonia).

(Only the 0.5 micron carbon block filter removes trihalomethanes, pesticides, volatile organic chemicals and 99.95% of giardia and cryptosporidium cysts.)

A Carbon Filter will usually lasts approx. 4-6 months ,depending on micron rating for the filters, usage and the quality of your tap water. The best way to determine when your Carbon Block Pre-Filter needs replacement is to use a chlorine test kit. Any chlorine level above 0.1 ppm will cause damage to the membrane and indicates that the carbon block filter must be changed.

I was told by the people at Spectrapure that carbon, especially GAC, will break the chloraimine bond and remove the chlorine and the DI resin will remove the ammonia.
I run a 5 micron carbon block, a GAC cartridge, then a 1 micron block before my RO membrane.

chloramine is nothing new, most municipality water systems are going to be mandated to use it when the new federal drinking water gidelines come out. chlorine itself is a instantanious steralizer with no real residual effect so most places where the water has to travel a distance there is no chlorine left in your water when it gets to you, by using chloramine it insures the disinfectant propertys of the water last untill you use it protecting you from older pipe sections which may be contamanated.

Kamloops uses RO for its water, but also adds chloramine.


the seymore water plant will use UV and Ozone and is and will still be using chlorine or chloramine, but at a reduced amount due to the UV and ozone. it will also be added at distrabution points. (it is writen right on the brochur for the plant.)

In victoria we have had chloramine for as long as I can remember and all I did was run different filters. for my system I ran a 25 to 1 micron absolute membrain (bigger 4x10") then I ran two carbon blocks, then an amonia guzzeler (home depot canuck rubber and a few other places have these. might be a different name but there for filtering out amonia.) then went into my RO and through my DI.

Steve

there is a reason for that. its called sales. chlorine will damage the membrain so in a household system people are usaly told to replace there prefilter and post carbon every six months and there ro membrain every year.

I used my RO membrains for seven years befor they started to degrade, and I atribute that to a proper selcection of prefilters and religious back flushing.

Steve