RO unit expansion

[buffalo123]

I have a spectrapure Ro unit and would like to add another membrane to the unit , I already have the second housing and the membrane anything else i will need. Anyone knows the procedure? Hooking up good ro water coming out of the old membrane to the inlet of the new membrane , waste water from old membrane hooked up to waste water new membrane??

[Icefire]

you need to hook the waste of the 1st membrane to the inlet of the second membrane. be sure to have flow restrictor on each membrane.

That way you'll get way less waste water

[Buckeye Hydro]

Buffalo - please email us and we'll email you a set of instructions with a plumbing diagram.

With membranes plumbed in series you use only a single flow restrictor.

Russ

[rbursek]

Ice,
why would you put the waste to the second one inlet? Waste is waste.

[AZDesertRat]

Spectrapure also has the directions on their website.
http://www.spectrapure.com/huds/DUAL.pdf

You will need a different flow restrictor.
I had a dual membrane MaxCap system until just recently and got 240 GPD at 99.23% rejection rate using SpectraSelect hand tested membranes in both.

rbursek, he is correct, thats how they work.

[rbursek]

DR,
I would think you take the good out from the first membrane and run it to the inlet of the second one, maybe I just do not understand what he wants to do, but always learning.

[rbursek]

Got it, run the waste to the other one to filter and less waste overall for the amount of good water, sorry Ice, I thought he wanted to double ro it.

[buffalo123]

thanks for the responses , double membranes ,running the water through the two membrance for even better water quality.
I happen to have the housing and the membrane and figure why not use it.
Is there any advantage to running the waste water through again? i figured the good water through the second membrane would be better; don't really know

[rbursek]

If that is what you want to do, I would think 1st membrane out to the 2nd one in, waste goes to waste, but a cheaper more effiecient way is 1 Ro membrane, then thru a Di, the di runs no waste water, just on the 1 ro.

[shyland83]

Yeah unless you have a water quality issue i wouldnt think it was necessary. Wouldn't you end up with twice as much waste water and slightly higher quality water?

[kcress]

That is really a poor idea. Very wasteful. Not good for the membrane. You will have endless problems with maintenance, and continually varying water quality, which can be worse than steady quality of a lower level.

If you want better water quality then follow A SINGLE membrane with a DI column. Don't run membranes in series.

[buffalo123]

well i guess i don't really need to do it as i already have it hooked up to DI. I just thought i would use the extra membrane & housing.

[alpine]

Buffalo did you notice what BuckeyeFS does for a living?I think its safe to say that he knows what hes talking about better then what anybody else who has posted on this thread.I would take his advice and run with it.

[Icefire]

Running 2 membrane in series (waste goes to the 2nd membran inlet) get you near twice GPH and you waste a lot less water.

If you consider that for each gallon of RO water you get you waste 4 gallon in the drain, with a dual membrane for each gallon you get you waste just a bit more than 2.2 gallons only.

So if you still don't wan't to do it, I'll pay shipping and send it over :) I got an old 25gpd and really need more than that ;)

[laverda]

I run two membranes age get more water and less waist. Well worth it in my opinion. The only thing I do different then the Spectrapure diagram is the out puts are not T-ed together. But I also do not have an auto shut off.