rodi water

gearhead · Jun 21, 2019

I know this is a loaded question but how often do you think you should change the carbon block filter in your RO system? I know carbon stops working pretty fast in your sump. But it has a lot more flow going through it too I guess. I just got a letter today from EPA about the groundwater having high benzene from a gas station down the street. They're saying 2320 ppb in the nearby water supply. I use my well water for my system. I did some research and the carbon should remove it but should I change it more because of this?

Bayareareefer18 · Jun 21, 2019

gearhead said:
I know this is a loaded question but how often do you think you should change the carbon block filter in your RO system? I know carbon stops working pretty fast in your sump. But it has a lot more flow going through it too I guess. I just got a letter today from EPA about the groundwater having high benzene from a gas station down the street. They're saying 2320 ppb in the nearby water supply. I use my well water for my system. I did some research and the carbon should remove it but should I change it more because of this?

You're right I think that's a tough one because I'm sure a lot depends on your water. I think general recommendation is 6 months. Do you run dual carbon blocks?

Randy Holmes-Farley · Jun 22, 2019

I only change them when they clog, but if yours rarely clog, then I’d change them at least once a year.

Randy Holmes-Farley · Jun 22, 2019

In general, the utility of carbon in ro/di is chlorine/chloramine removal. Do not worry about organics if the water is drinkable by people. In this case, that’s a lot of benzene. Not sure how much of a concern it is.

Randy Holmes-Farley · Jun 22, 2019

The ro will remove a good fraction of it too.

gearhead · Jun 23, 2019

we don't drink it now that we got the letter from EPA. I was using ro drinking water in 5gal containers and was going to start the ro thing because it shows 50ppm on tds. The letter says that anything over 5ppm is not safe for human consumption. I researched the way to remove and they say carbon block but it says it reduces it a lot but never says all. It also says rodi will not remove organics. How would I get it tested I am scared to use it.

gearhead · Jun 23, 2019

Also what is deionizing the water do you see on the aquarium ro units but they don't on the drinking units they tend to have the duel carbon block mine has the di unit. They also tell you not to drink the water because of the deionized.

Bayareareefer18 · Jun 24, 2019

gearhead said:
Also what is deionizing the water do you see on the aquarium ro units but they don't on the drinking units they tend to have the duel carbon block mine has the di unit. They also tell you not to drink the water because of the deionized.

The DI stage will remove what the membrane could not. The DI should take your water down to 0 tds. I get about 3 tds into my DI then 0 coming out.

If you still want ro for drinking you can tee off the system between the membrane and the DI