RO efficiency changes during the day

[reefkeeper1]

My tapwater has a TDS of 186 PPM.

At 4 PM on Sunday, my RO filter brought it down to 6 PPM.

At 1 AM on Monday, it was down to 2 PPM.

At 7 AM on Monday, it was all the way up to 20 PPM.

I guess the city-wide water pressure is changing enough during the day to affect the efficiency of my RO membrane. The changes make sense considering the water use during the time of day I listed above.

Does anyone have experience with a booster pump for their RO filter? I've been looking at the Aquatec 8800.

 

[sfsuphysics]

Don't forget the temperature changing too, although I can't imagine why it'd be "better" at 1am... either way, use some DI resin to fix that problem up

 

[reefkeeper1]

I thought it would be better at 1 am because not many people are up at that time using water, thus, the water pressure would be highest during this time. I figure the water temperature stays about the same throughout the day since it's piped underground.

I do have DI after my RO output. It just makes sense to me to get a booster pump so that the DI doesn't get used up as quickly.

 

[reefer on a budget]

it could also be the temperature throughout the day that is affecting the tds reading(unless you have one of those that has temp compensation). think of a cheapo tds meter having a bunch of resistors inside that vary considerably versus temp and affect readings.

theoretically, a functioning ro/di should bring the product water to 0.

*edit: just noticed sfsuphysics just mentioned that...figures a physics guy would know...:smokin:

 

[sfsuphysics]

Bah ROAB, that's a chemistry question not a physics one