RO modifications question

[BMan]

Hello,
I want to add a second RO membrane to my system. When doing this, do I need to change my flow restrictor ? My current system is a Kent Marine Hi-S with a 75gpd membrane and flow restrictor. I just bought a used Kent Marine Hi-S and want to use the RO to piggyback my RO and increase my gpd output.

 

[Water Dog]

Just replumb so that the flow restrictor is after the second membrane. Just make sure you have enough water pressure so that you can effectively run 2 RO membranes. Here is a good BRS video on setting up a second membrane.

 

[BMan]

^ Thanks. I knew that mush already. My take away from the video is he never mentions the flow restrictor so I assume it doesn't need to be changed. I just need to buy the two clips to hold the second RO. I may as well order a couple of pressure gauges while I'm at it.

 

[pecan2phat]

At what point do you guys feel that a booster pump is needed?
I use to have 90-95 psi while the unit was making water and 40-45 psi in flush mode before I moved, now I have 65-70 making and 25-30 flushing.