How to combine two different RO/DI Systems?

[VelasCorals]

I have two different RO/DI systems and I was wondering if they could be combined to create 1 more efficient system. Anyone ever combine two systems? If so, how is it possible?

One system is a 3 stage and the other is a 4 stage.

Thank you in advance for the help!

 

[Usctom]

Are the ro membranes the same gpd? BRS has a kit to add to there 75 to make it 150.

 

[VelasCorals]

One is a 75 and one is a 100 I think... Is it as simple as putting the waste into the input? That doesn't seem right...

 

[AZDesertRat]

Its not quite that simple, you need a different flow restrictor also to keep the waste ratio correct.
Take a look here to see how to plumb a dual membrane system:
http://www.spectrapure.com/huds/DUAL.pdf

More sediment or carbon filters are counterproductive so stick with one good 1 micron or less sediment filter and on 1 micron or less carbon block. Dual full size DI filters can be a good thing though especially if you can test the TDS between DI filters and rotate the second DI into the first position once it is exhausted getting more life out of your resin. That or using different resins such as Spectrapures MaxCap in the first and SilicaBuster in the second.

 

[VelasCorals]

Thanks for the feedback. I think I'll just sell both of them for cheap and then upgrade to a bigger and better systems.