Dual RO Membrane Hookup?

[pixelpixi]

I just bought a used spectrapure 5 stage RO/DI. It has dual RO membranes, and I'm trying to verify that they're hooked up propertly.

I guess I was assuming that they'd be hooked up in parallel (feed from carbon filter to both RO unit inlets, both waste outlets to waste line, both clean water lines to the DI stage) but that doesn't look like how it's been done. Should it be in serial instead? It looks like the waste line only comes out of one RO unit, which seems strange.

TIA for any advice.

 

[buck50bmg]

The second membrane is for the waste of the first. so you get less waste.

 

[kgross]

Depends on what you want out of the unit. If you want less waste water hook them up in series, but you will not get quite as much good water out of it, if you want max good water, hook them up in parallel, but you will get more waste water.

Kim

 

[pixelpixi]

Okay. Thanks, guys!

 

[wife no likey]

As stated by buck50bmg, the proper hookup is waste of 1st to input of 2nd.

With a proper flow restrictor, you should be getting about 1:4 ro/waste out of the 1st membrane. With that being fed to the 2nd, you are now effectively doubling your output, while still substantially decreasing your waste. Personally, I use three.

I don't see why you would want to run them parallel.

 

[kgross]

If you put them in parallel you will get more total water output, with them in series you do not have as much pressure on each membrane, so you don't get quite as much flow out of each membrane.