How many RO membranes?

[Ma98tron]

Hello,
I’m new to this website and had a few questions on reverse osmosis. I have a aquatic 8800 pump, 5 micron filter and one 100 gpd membrane off amazon. It’s not an long as the 4x40 membranes that I’ve seen, will it work and how many do I need for optimal use. I currently only have one? Thanks

[mol1jb]

I believe most of those type builds with the pump your mentioned run from 3-6 membranes.

[Ma98tron]

What is the advantage of using more then one membrane? Also do you need a needle valve on the end of your concentrate line?

[Bricklayer]

If you plumb membranes in series your basically getting higher concentration but sacrificing flow.
Series means that sap goes into first membrane then the concentrate from that membrane gets fed to the next membrane concentrating it even higher.

Plumbing membranes in parallel means your hp pump is feeding each membrane individually this processes sap faster but at a lower concentration.

[Ma98tron]

Another question I had... the membranes are rated like 100 gpd or 50 gpd. Does third mean that the max amount of sap that will flow through it is 100 gallons per day. And can you have two different rated membranes running in series such as a 100 and a 150 gpd?