What happens when changing RO's GPD?

[Leroy]

What determines and RO/DI's amount of water made GPD? Would it be in the case if you had a 75 GPD unit and removed the cartridge then inserted a 100 GPD cartridge and the 100 GPD membrane would you have modified the 75 to now 100?

 

[JayM]

the membranes are the same size, the restrictor valve in the unit may need to be changed.

On my water general unit, which came with a 100GPD membrane, I swapped it to a 75 for the higher rejection rate. Water general uses the same restrictor for both, so I didn't need to change that too.

you should check with the manufacturer to see if you need to change restrictors if you switch membranes from 100-75 or vice versa

 

[Leroy]

OK, help me out with a few unknowns for me right now? What is it meant by rejection rate and what are the restrictors?

 

[BOSTONBAKEDBEAN]

restrictor causes pressure to force water through the ro membrane, otherwise all the water would go down the drain. different membranes operate under different pressure hence they usually need to be swapped out.

I know spectrapure caries em for like 4 bucks.

 

[Leroy]

Ah, got it now. So it's makes sense that some unit have control valve restrictors and other don't so that the waist water is already pre-determined for that unit.

 

[biggyclops]

higher GPH usually produce inferior water (higher TDS) from what i read.. but i think that is more for those 200 gph type of ro filters..