Someone building his own home brew RO system mentioned to me there are Ultra High Flow RO membranes out there
anyone know if these are in any of the units for sale at WCR or anything more about the flow differences in RO membranes?
I thought RO was an RO was an RO, guess not
[MENTION=36915]perrytait[/MENTION]
[MENTION=4]Alex[/MENTION]
[MENTION=67]Beautiful View[/MENTION]RO filters come in all shapes and sizes from 50 gallons per day up to industrial setups of a few million gallons per day.
RO filters are surprisingly simple bits of kit - simply get a 4040 housing and a HF5 membrane, add a bit of tubing, a couple of pre-filters & a flow restricter and you can build your own RO cart in a couple of hours.
If one RO membrane doesn’t produce water fast enough you can plumb another next to it,… this can either be done in parallel for maximum water output or in series with the waste water from the first membrane feeding the 2nd membrane - this setup will reduce your water wastage considerably. I’ve seen 4 RO membranes connected in series before on a system that produced 3 parts pure water for every part waste water. The membranes further down the line will need replacing sooner & flushing more often though,…
You can build RO systems to suit any size of business,…
I’m not so sure that putting RO membranes in series is such a good idea if you use the waste water of the first stage as input to the second stage.
First of all, RO can only perform well with good pressure. The waste water coming out of the first RO membrane will provide nowhere the same pressure from tap, so right there already, your second RO won’t be performing optimally due to weak pressure from the first waste line. You will progressively has weaker flow each time you go through another RO stage in series.
Secondly, the TDS of the first waste line is easily twice as much as the tap’s TDS. Even if there’s good enough pressure out of the firs waste line, the permeate water coming out of the second stage RO in series will have twice as much TDS reading as the first stage RO. So the water purity will progressively get worse in series.
I don’t see good justification to put RO membranes in series. The waste water saving is not worth the depreciated performance, flow rate and purity to connect them in series.
I agree with you - personally I’d always plumb filters in a parallel arrangement - - but in places where there are big restrictions on water wastage this setup has its advantages,…
i believe a top of the line RO membrane for our use falls in the 2500 GPD range and rated as 'low energy’ . The replacement membranes for the Wash-iT and Hydro cart fit the bill.
Yep - thats the 40" x 4" HF5 membrane isn’t it? Its one of the best performing ones for window cleaning use.
@Bill WCR
Don’t mean to hijack the thread but I have a related question…can RO’s be mounted horizontally? I know there can be issues with DI on its side but a quick search didn’t bring up anything regarding the RO’s.
Yep - A lot of manufacturers mount horizontally - the only place I’ve seen vertical is on carts. 
I think the only cartridge that shouldn’t be mounted horizontally is the DI one. That’s because you want the DI resins to be packed down (with the help of gravity) to avoid water channeling. So the water flow in the DI container should be going from top to bottom through the resin. So DI containers using a riser should be positioned upward, but DI cartridges without a riser (like the one on the Wash-iT) should be upside down so water goes through the resin from top to bottom.
thanks Mark, and with the picture of the one in the last thread as I post
so you mean the wash it is not this membrane but can be replaced with this hi flow one instead?
a couple people have told me 2 hi flows in parallel give the gpm output from a 40 psi spigot comparable to a DI tank and that a wpole can be run ‘live’ without booster pumps or delivery pumps
I know the wash it runs ‘live’ too, but nothing close to the gpm flow of a DI tank (i’m talking .5gpm out of the brush head at 45ft height after running thru 350ft of 3/8 hose.
If all I need to do is hook up another RO membrane in parallel to my wash it paperweight, i’m in!
I’m afraid my knowledge on RO’s isn’t where it needs to be to confirm whether your suggestion of 2 ROs is sound. Hopefully someone with more knowledge will step in.
maybe an RO setup with a flow regulator that the user has ful control over would work better for you if you were going to go the DIY route. I know the Wash-it has flow regulators as well as auto balance (between waste water and pure water) built in which you have no control over. Perhaps his is what you feel you need to get around to have a system perform in your area and to your needs (4 stories without a pump).
Yup - that’s what’s popular with the UK WFP’ers anyway - its very efficient even down as low as 50 psi (Higher is better of course), which means that the majority can use it without the expense and hassle of a booster pump.
Add a housing and pre-filters as well as a restricter valve on the waste & you’re good to go. 
[MENTION=4]Alex[/MENTION]
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