Cleaning RODI Unit

[pazzo40]

I am going to replace the filters and membrane of my RODI unit. Instructions say to wash the inside out with soap and bleach. Could I just do it with warm water and bleach? Any type of bleach ok? How long should the unit dry after before I use it again?

[AZDesertRat]

My recommendations are as follows:

 

Shut the water supply off, disconnect the line leading from the carbon canister up to the RO membrane at the RO housing end and stick this in a bucket or sink. (This protects the membrane from chlorine) Unscrew the sediment and carbon canisters and remove the old filters then screw the empty carbon canister(s) back on. Add no more than two tablespoons of regular unscented bleach to the sediment canister and screw it back on. Slowly open the water supply and fill the empty canisters until water starts to exit the disconected line then shut it off and let the canisters soak for 3-5 minutes.

 

Turn the water supply back on and flush the water out until there is no chlorine odor left. Shut the water off, install ONLY the sediment filter, turn the supply back on and flush the sediment filter for a couple minutes to remove any glues or binders used in the manufacturing process. Shut the water off and install the carbon block, only the first if you have two (which I do not recommend) and again turn the water on and flush the carbon dust and fines to waste for a few minutes. Install the second carbon f you have two and do the flush again.

 

Reconnect the 1/4" line to the RO membrane housing and you are ready to go.

 

If you are replacing the RO membrane and DI filter also you can skip disconnecting the line, remove the membrane and DI cartridge at the same time as the others and flush the bleach solution through the RO housing and DI canister too. Normally at 6 month replacements it is just the sediment and carbon blocks that get replaced. If it is just the DI getting replaced you can rinse the canister with maybe 1/2 spoonfull or bleach in some RO/DI water.

 

I don't use soap and wate unless things ar visibly dirty and I am completely disassembling the system.

[pazzo40]

I can't even get the housing unscrewed

[AZDesertRat]

Make sure the pressure is bled off, if you have a float valve raise the float to relieve pressure.

 

When reassembling the system wipe a very thin coating of edible silicone grease on the O rings then screw them only hand tight plus maybe a little tweak with the filter wrench if needed, they don't have to be super tight since the O ring does the sealing.

[pazzo40]

I've taken the whole unit apart so it's just the sediment and carbon. I still can't get it to move

[AZDesertRat]

It may take a large pair of channel lock pliers or a strap wrench the first time. Once you coat the O rings with silicone grease it should be easy from then on.

[pazzo40]

I messed up my thumb trying to open it. I hope I didn't dislocate it lol.

[pazzo40]

So I finally was able to open the canisters. Since I am replacing all filters including the membrane I can just put 2 teaspoons of bleach in the sediment canister and run the water until it starts to come out of the waste line then let it sit for 5 min then flush water through it for 5 to 10 min then start to put the new filters in? Should I run water through each filter to flush it or can I do this all at once?

[AZDesertRat]

You can do it all at once.

[pazzo40]

Do I need to let all the water dry out after I flush the bleach out before I put in the new filters? LFS told me bleach is non toxic once it evaporates. Not sure how true this is.

[AZDesertRat]

Not quite true but once you flush it out and dump the rest there shouldn't be any bleach left. Where people run into trouble is when the dump a bunch of bleach in and it sticks to the plastic. Fresh bleach is 50,000 parts per million so very strong so it only takes a couple spoons full to do the job, no more than that.

[pazzo40]

So finally all done, replaced sediment, carbon, membrane, and di. Recommend just flushing the first 5 gallons? I'm running it through the entire unit at once.

[AZDesertRat]

Flush the filters individually so the crud does not plug the next filter downstream. I detailed this flushing method earlier in this thread. This includes flushing the new sediment filter first, then the carbon, then the RO membrane and finally the DI, this is important.

[pazzo40]

You can do it all at once.

 

Mistook this as I can just run the water through the whole unit at once. Oh well filters were from 2010 don't think these new ones that I flushed all at the same time can be worse.