RO Question

[Just2Many]

SO I have two units and was wonder can I hook them together? Save some water? I know that I can somehow link membranes together but what about whole units? Or is it just easier to add the membrane to the main unit? Also if I do can they be two different gph rating?

[Fishbulb2]

Hi,

There would be no need to fully combine the two units because you would be using twice the prefilters and that would just be more expensive to maintain. Ideally just move the membrane over. Typically, it's two 75 GPD membranes that are combined and then you need to work out the correct flow restrictor to make sure each membrane is seeing a 4:1 waste to permeate ratio. You might be able to combine different gpd membranes but you will need to work out the flow restrictors. Make sure to hook up the membranes in series and not parallel. This will give you less waste water (waste water of first membrane feeds second membrane).


FB

[Just2Many]

Ok so if i use two 150 gpd membranes then a 300 gph flow restrictor? Or a 150?

[Fishbulb2]

If you were using two 150gpd membranes in series, then you would want a single 150 GPD flow restrictor. You would simply take the prefilter water and run it into the first membrane. Then run the permeate into your collection reservoir. Next run the waste line from this first membrane into the inlet of the second membrane. Now collect that membrane's permeate into your storage container as well. Place a single 150 GPD flow restrictor on the waste line of the second membrane. This will give you a 2:1 waste to permeate ratio and both membrane's will see basically the correct waste ratio.

HTH,
FB