Advanced RO/DI Setup Question

[GlassMunky]

Currently I have running a 5 stage 75GPD RO/DI unit. My boyfriend had been running a 4 stage 75 GPD RO/DI unit. Since we've now moved in together and won't be running both of them I got thinking about possibly hooking them up together to get an 8-stage RO/DI. Would this setup work???

In from source water-sediment filter-2nd sediment filter-carbon block filter-2nd carbon block filter-chloramin block filter-booster pump-RO membrane-DI cartridge- 2nd DI cartridge.

I figure the added (doubled up) pre-filters would help make the RO membrane last longer, and help give me 0 TDS reading. Could I or should I run 2 RO membranes too? Are there any issues with running that many stages on the RO? I've only ever run my 1 unit stock from the company.

Is anyone running a similar setup?

 

[DaveK]

Consider that one RO/DI unit will create water with 0 tds. There is no advantage to trying to make an "8 stage system".

The thing you can do is to run them together, so you create twice as much water over the same amount of time.

If you want to do the plumbing you could run one set of sediment and carbon block filters and feed the output from that into both RO membrane units.

You could also just keep one unit as a spare.

 

[GlassMunky]

I figured with all the extra pre-filters, the RO membranes would last longer? And less changing of the pre-filters.
Also was thinking I could run the waste water from the first RO membrane into the second RO membrane and then T both the good water lines back together going into the DI chambers therefor cutting down on the amount if waste water produced, and at the same time having both RO's going which would also increase good water output.

Is this thinking correct?
I see BRS has an add on RO membrane that basically does this, but since I have everything already figured I could try it?

 

[Mike Johnson]

This is hard to explain and it's not that late - been a long week. Go to this site and rotate the picture so you can see the back of the unit. You'll see that the two RO membranes are run in unison with the same water pressure, which allows twice as much water through. Or you can get a booster pump to increase your pressure and get more water to permeate the membrane. Running the second RO membrane off the waste water line will only back up your pressure and both membranes will let less water through. Hope you understand what I'm saying?

I would run the 5 stage and either sell or keep the other one for a back up. Unless you have a 1000 gallon tank 75 gallons a day is all you'll need.

http://www.bulkreefsupply.com/brs-5-stage-water-saver-plus-ro-di-system-150gpd.html

 

[GlassMunky]

I already have a booster pump, so pressure isn't an issue.....

 

[GlassMunky]

And actually, it says in the video, that the second RO is running of the waste from the first. The y on the back is so that both the good water lines go back to the single DI stage.

 

[Mike Johnson]

Okay, I guess I'd better just go to bed.

With a booster pump you'd have enough pressure to pull it off anyway.