Difference between RO/DI and just RO filters?

[thefedz]

hey guys

I was just wondering what the difference was between water filters that just have a RO component versus filters that do both RO and DI?


I have an old RO water filter that I need to change all the filters for that I want to start using. I was thinking of getting an RO/DI unit instead? Would it be worth it?

I can't seem to find anywhere what the deionization process does for the water that that reverse osmosis component doesn't already do...

Also the flow rate of water filters... does it only depend on the flow rate of the R/O Thin Film Composite membrane?
I mean if i buy a 10 GPD unit.. when i replace the TFC membrane, can i replace it with a 50 GPD unit and get 50 gallons out of it?


Thanks

 

[ZooKeeper1]

RO DI does produce water with lower TDS. A DI unit does the final cleanup of what remains after passing through thr RO filter. It is an exchange process rather than filtering. You should get the largest GPD unit you can afford. More GPD means more RO membrane. I think it would be a waste of money to do what you are proposing

 

[Fatal Morgana]

DI will remove ions that the RO membrance can't. There are many ions that can pass thru the membrance due to their small size, but will be caught by the DI process. This is why the DI give extra purity to the RO water.

>...I mean if i buy a 10 GPD unit.. when i replace the TFC membrane, can i replace it with a 50 GPD unit and get 50 gallons out of it? ...

Yes. The difference between a 10 GPD RO and a 100 GPD RO is just the membrane. This is not true for commerical RO, however, but that's separate issue.

You can always upgrade your RO to a RO/DI by getting a DI add-on kit that basically a post-filter for the RO water.

And more importantly, Welcome To RDO!