Issaquah vs Mercer Island city water

[MrGone]

I thought this was interesting, I brought my RO/DI machine into my dads office to fill his tank and its crazy how quickly the sediment filter is turning brown from Mercer Island water compared to Issaquah water. I've put at least 800 gallons through it in Issaquah and it barely had a hint of tan. I'm at about 200 gallons now here in Mercer and its darker than a paper grocery bag. I figured Mercer Island would have cleaner water because of the affluency but now I'm thinking maybe Issaquah grabs water from the rivers and Mercer Island gets it from Lake Washington?

 

[returnofsid]

Are you running the tap at the same, or at least near the same, temperature? Different temperature source water will effect the efficiency of an RO/DI unit.

How about pressure? Large differences in pressure will also effect efficiency.

 

[MrGone]

I'm running them off the cold water line to the sink, I'm not sure of the exact temperature. Its the Puratek unit with the booster pump, the gauge reads the same at both locations, about 130-140psi.

Do temperature and pressure effect the sediment filter? I just thought it was funny how quickly it was turning brown here.

 

[returnofsid]

I think temperature and pressure mainly effect the RO Membrane's efficiency. Typically, your filter will run more efficiently with "luke warm" water, than with straight cold water. Were you running cold water at the in Issaquah, as well? If so, then temperature wouldn't have effected any change in efficiency, since water was cold, at both locations.

It could very well be that the water is just "dirtier" where you now are. I wonder if it could have anything to do with how the water is "treated," by any water treatment facility. Maybe Mercer Island water is treated differently, making your filters work differently.