Copper and Zinc in RO DI Product Water Bin

[Trenton Henderson]

Got my ATI ICP test results back. They state that I have 4.62 ppb Copper and 7.16 ppb Zinc in my product water. I run 2 RO Membranes with a 1 micron sediment filter and two carbon blocks. The entire unit is followed by a canister of mixed bed DI resin.
My tank’s test reported undetectable copper levels though, which confused me. Though I do run a reactor of carbon.

My home TDS is ~150. The RO membranes suck out all but 2 TDS and the DI takes care of the rest. I’m thinking about adding a second mixed bed DI stage, but not sure what you all thought.

I live in a condo that was built in the 70’s, so I’m thinking the pipes leach a good bit of copper.

 

[KrisReef]

That sounds more like your source water (w/metals) before the RODI filters them out? Otherwise, It's a mystery.

 

[Trenton Henderson]

That sounds more like your source water (w/metals) before the RODI filters them out? Otherwise, It's a mystery.

What’s strange to me is that Cu is in the RODI water, but not the tank. The only thing I can think of is that the GAC reactor pulled it out.

 

[mginster]

Got my ATI ICP test results back. They state that I have 4.62 ppb Copper and 7.16 ppb Zinc in my product water. I run 2 RO Membranes with a 1 micron sediment filter and two carbon blocks. The entire unit is followed by a canister of mixed bed DI resin.
My tank’s test reported undetectable copper levels though, which confused me. Though I do run a reactor of carbon.

My home TDS is ~150. The RO membranes suck out all but 2 TDS and the DI takes care of the rest. I’m thinking about adding a second mixed bed DI stage, but not sure what you all thought.

I live in a condo that was built in the 70’s, so I’m thinking the pipes leach a good bit of copper.

Have this exact same issue with my recent test to ATI in September. Copper, Zinc and Silicon detected. Pre-DI TDS was 3 and post is always 0.

Also as you stated copper is only in RODI, undetectable in tank.

 

[Fredinva]

Im in the same boat, so to speak! My water test shows high copper in my tank. Obviously, the Cu is in the RODI and comes from my copper plumbing, RODI systems cannot remove all the bad stuff as we hoped. Some copper, zinc, and silicates get through most RODI systems that still show as 0 TDS! I have recently changed one di canister to a silicate buster di resin, and I have some Cuprisorb on the way. Hopefully the cuprisorb will take care of the copper. After two or three weeks I will have another ICP test done.

If copper is in the RODI, the same amount has to be in the DT,,,,,,