how to sanitize an RO unit.

hey all! i was wondering if any of you could give me a detailed description of how to sanitize a used RO/DI unit? im wanting to make water when my TDS meter arrives but need to sanitize first. thanks!

 

What kind of unit is it? If you have the make/model number that would be best.

 

Bleach water? Obviously take the filter media out.

 

water general Rd-106. any ideas?

 

Unscrew all the filter sumps (canisters) and remove the old filters, in you case I believe that is a prefilter and two carbons.
Now, very important, unscrew or disconnect the 1/4" line leading from the carbon canister up to the RO membrane housing at the RO end and stick this tube in a bucket or the sink. If its too short temporarily replace it with a longer piece for flushing.

Add two to three tablespoons of regular unscented bleach to the prefilter housing, more is not better in this case fresh bleach is 50,000 parts permillion strength and very powerful. Screw the empty sumps back on and open the water supply until they are all full and water starts to exit the disconnected line. Shut the water off for 3 to 5 minutes and let it soak. Continue flushing until the smell of chlorine has passed.

Remove the prefilter housing only and install the new prefilter. Reinstall it and flush for several minutes to remove any traces of glues and binders used in the manufacturing process.

Next install the first carbon block if you have two and flush it for several minutes to flush out and carbon dust or fines. Do the same with the second one if you have two which I personally do not recommend, one high quality carbon is more than sufficient but thats another story.

Now reconnect to the RO housing and you are ready to make RO water. If you have DI you will need to do those seperately as they are downstream of the membrane which would have been damaged by the bleach had you not disconnected it. You can add a spoon of bleach to the DI housing and swish it around for a few minutes and they will be disinfected.