Cleaning/Sanitizing RODI Unit

[jager]

I need to clean/sanitize my rodi unit. It is a typhoon III. I have read some of the instructions on how to do this, although I didn't see anything in my actual manual. Any tips or recommendations on doing this. I know to remove the filters and ro unit. Then do I use chlorine bleach? Do I need to pickup a chlorine test or just go by smell.

 

Thanks

[AZDesertRat]

My personal method is as follows:

 

Turn off the water supply, bleed off any pressure and remove the old prefilter and carbon(s) from their housings. Now, VERY IMPORTANT, disconnect the 1/4" line which leads from the carbon filter up to the RO membrane housing at the RO end. Stick this line in a sink or bucket, if it is not long enough you can substitute a longer piece temporarily.

 

If the housings appear dirty scrub them with some dishsoap and rinse well. Add 2 to 3 tablespoons of regular unscented bleach (Clorox etc.) to the first or prefilter housing only and screw the empty housing back in place. More is NOT better in this case, fresh bleach approaches 50,000 parts per million chlorine so it does not take much. The more you use the harder it is to rinse out.

 

Turn the water supply back on slowly so you fill the empty housings and water begins to exit the disconnected line. Let things stand and soak for 3 to 5 minutes. Now open the water and let the bleach run out the disconnected line until any scent of chlorine is gone.

 

Unscrew the housings and drain the water.

 

Install the prefilter ONLY and reinstall the other empty housings. Open the water supply and flush the prefilter for a few minutes to remove any binders or glue and any antimicrobial coatings it may have.

 

Next install the carbon block, if you have more than one install only the first one and do another flush to remove any carbon dust or fines so it does not plug anything downstream. Do the same with the second carbon if you have two.

 

Finally reinsert the 1/4" line you disconnected previously and you are ready to go.

 

If you want to disinfect the DI filter you can do something similar with it by temporarily attaching that line you disconnected from the carbon to the DI IN fitting and adding it to the chain or array and doing it last. This way you completely bypass the RO membrane which cannot stand any chlorine or bleach.

 

If the system sounds like it has air trapped inside it you can pick the RO/DI up while it is in operation and rotate it around in different directions to release any trapped air pockets.

 

Thats should do it. Whatever you do do not get any bleach in the membrane. If you think the membrane housing needs disinfecting too, remove the membrane and do the housing empty.

[ScubaJ]

Awesome write up AZ. Follow up question.

 

When should we do this? Every 6 months, year? Gallons used?

[AZDesertRat]

Most vendors, if they mention it at all, recommend at least annually. I do it every 6 months when I am doing my filter replacements. The system is already out of service and it only takes an additional 10 minutes or so when you get the hang of it.

[jager]

Sweet, thanks for the info.

[ajmckay]

Good info!