Ro membrane filter sizes

[Papa Doug]

My ro unit has run the last three yrs. on its original 100gpd membrane. The tds reading between it and the DI have been slowly rising, so figured time to change membrane.
Switched to a 50gpd size, as its suppose to be the best size for making better water. My wife, who makes all the ro water, as all the waste goes towards the wash, said it makes about half the 100 did, and about the same amount of waste water.

Of course thats not an accurate measure or anything but if true, then IMO, somethings wrong or its a poc. Was under the assumption a lower gpd output was more efficient in both water quality & rejection rate. And to boot, my tds is still reading 8ppm from the new membrane.

[Papa Doug]

So I did some laundry last night and made ro water. For sure the 50gpd membrane is big time slow in making water but it seems to produce the same amount of waste as the 100gpd. Thought they were suppose to be more efficient. What a waste of $70

[Papa Doug]

So the answer is,

have to change the flow restrictor also, if changing membrane sizes.

[Papa Doug]

Removed my bypass. Apparently the flow restrictor is in it. Stupid place if you ask me. Placed the new flow restrictor in the waste line.

My wife said it increased the amount of ro water, so thats good but she said still getting roughly same amount of waste water. I,m thinking this 50 gpd is going to a friends place and I,m going back to my 100 gpd.