ro rejection rate
 

Difference between the 50, 75, 100 & 150 GPD membranes?
The major difference, besides how much water they can make, is the rejection rate. Normally, the lower the GPD volume, the higher the removal rate is.

The 50 and 75 GPD membranes have about the same rejection rate of 97%. The 100 GPD has about a 90% rejection rate. The 150 GPD membrane is a different story. It allows for high volume without a big drop in the rejection rate. It has about a 97% - 99% rejection rate.

from here, new to me about the 100 gpd membrane.

Yes, this is why I never recommend 100 gpd systems to anyone. I try to tell everyone who is interested in buying an RO to make sure they don't buy the 100 gpd to try to get the word out since many people have no idea.

For those that already have 100 gpd RO systems, it is easy to change. You just need to buy whichever membrane you want, and a flow restrictor that matches the gpd rating of the membrane. Bulk Reef Supply has them readily available for very reasonable prices. www.bulkreefsupply.com

If you are intresting in any RO system get kinetico the best water to use. :D
Any one else use kinetico?

Does these rejection rates apply to RO/DI units that use booster pumps to obtain 100GPD? I was looking at the Vertex Putatek model that says they get 1:1 waste water production. Right now I use a Kent Maxxima 60GPD model and it seems descent.

Booster pumps get you from 1:8 up to 1:4 .....good: rejection

My manual for my Kent Max60HiS states that the "Waste to product ratio" is 3:1 and it doesn't have a booster pump, do you think the manual is that far off? I've never filled two buckets at the same time to compare. The Vertex Puratek (100GPD model) claims nearly 1:1 product to waste water ratio, but with it's booster pump will the rejection rate still only be 90%? Does the booster pump have no effect on the membranes rejection rate? Just curious because the Vertex has built in TDS meter, Auto shut off, pressure gauge, etc for a pretty descent price.