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thewookie
03/05/2015, 09:35 PM
I was reading "WaterKeepers" intro to aquariums and I came across RO/DI which I am in the process of ordering. He makes a comment as follows, "The latter is the most important part: free chlorine in the water will destroy the RO membrane"....

I checked with my local water authority test results and the most recent they have states 1.5 Max and 0.8 avg for 2013 Free Chlorine. I believe the measurement is MRDL or MRDLG whatever that means.

I'm not sure I understand the implications when compared to WaterKeeper's comment above.

Tom

RocketEngineer
03/05/2015, 09:48 PM
You need a carbon block before the RO membrane in order to remove any chlorine that may be in the water. From the sound of it, you are on city water in which case I would think a 5 stage system is the best option. Typically you get a mechanical filter, two carbon filters, the RO membrane and then the De-ionizing resin. The two carbon blocks will make sure that no chlorine gets to the RO membrane.