RODI Filter Question

[Ed Vert]

I have been running a 28 Gallon Nano for a few years now. No issues.
After I moved to Poway, started getting green algae. Did the normal checks.
Then decided to check my RODI unit. 77 PPM coming out of the unit. Ouch.
So replaced the sediment filter, carbon. Upgraded from a 75 GPD membrane to a 150 GPD with the correct flow restrictor. And changed out my DI resin.

Flushed everything out. PPM out of my membrane is still high. 500 PPM tap. 55 RO, 3 ppm after DI.

I was hoping 40 ppm or less. Any ideas?

[SmilinAvnger]

What does your meter top out at? Does it go over 500 PPM? My water varies between 440-550 and comes out 0 PPM. haven't tested the RO output in a while... but I remember it being about 30... maybe?

Could your water measure so much over 500 that its too much for the membrane and DI? Maybe get a second carbon chamber? (mine runs 2 carbon chambers)

Oh and how about water pressure? Do you have enough to efficiently run the filters? About 70 psi I believe.

[maze531]

Did you flush the membrane? If I remember right mine was higher then expected at first too but then I flushed it and it dropped to like 9 after the membrane.


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[Dreamkeeper]

I would check your water pressure, do you have a pressure meter on the output of the unit? My readings run 70 psi, 440 ppm raw in, 13 ppm out of RO unit and always zero out of DI.

[Ed Vert]

Meter goes to 1000 ppm. Tap varies from 464-500~. Checked the Poway water report, that reading is about right.
I could run another carbon stage, I have another chamber for that. And since seeing the water report. Looks like they also use chloramines. So will add a granular activated carbon filter as the second stage.
I flushed all the filters including the membrane for about an half hour.
I guess pressure could be the problem. Will pick up a pressure gauge and check. The connection should be before RO correct?

[Ed Vert]

Aquatic Warehouse didn't have any gauges. So will have to check the other LFS.
I did notice when I was making sure the membrane was seated, the flow restrictor that came with it was a 600?
I already had a flash flush restrictor rated @ 1100, so I switched it out. Could that change my readings?

[SmilinAvnger]

I would go to home depot or lowes for a water psi guage.

[Ed Vert]

I finally got a pressure gauge installed. 30 psi. No wonder I am having issues with the membrane.

[Sancho]

30 psi for the house is low. Showers must suck at your house. Depending on how old the house is you can probably adjust it to 70 to 75 psi with no issues. Stay below 80 psi. You should check with the water utility in Poway to see what the pressure is at the street. Have you tried adjusting the regulator? You may need a new regulator or you might have some build up in the pipes.

[Ed Vert]

Showers do suck. I'll check with the water dept. for the pressure at the street. May have to get a booster pump.

[Sancho]

A booster pump is not a bad idea. But I would check you pressure regulator. I live at the top of a hill and I get 80 psi at the street. For some reason my regulator was set at 40 psi. Like you I was not getting 0 tds water and my rodi unit was not working efficiently. the waste was 6:1. I adjusted it for 70 psi my showers are much better and my rodi puts out 0 tds without a booster pump. My waste is now 4:1. I have lived all over San Diego and there are some places that just have low water pressure.

[Ed Vert]

I checked my regulator. And was able to adjust it to 50 psi before the membrane.
Now I get about 34 ppm after the membrane. Better.