Finding copper in my tank

[Evolution997]

Hello there!
Before 3 months i sent triton ICP tests and they found copper in my tank.
I made a therapy as they suggested with triton DETOX but im not sure it has completely dissappear.
The problem is that I can't find a source of copper in my tank, I have check everything on my equipment for rust etc...so I made thoughts that it could be in my Ro water.
Can this eroding plastic increase copper in the water?
It seems like rust but it's not as it is full of plastic, I think it's from the source of my water.
Please tell me your opinion about this and any other possible source and reason causing this.
Thank you!!

 

[lapin]

You can buy test kits for your fresh water source. Both copper and rust kits are avail. It might be cheaper to send in a sample to be tested.

 

[exnisstech]

Is your source water well or city water? We used to get rust stains when we were on a well.

 

[Evolution997]

Is your source water well or city water? We used to get rust stains when we were on a well.

I live in a city so my water source is from there!
But i'm almost sure that Ro water is the reason of copper. I'm planning to change all filters, tubes and all parts of Ro to be sure for everything

 

[Evolution997]

You can buy test kits for your fresh water source. Both copper and rust kits are avail. It might be cheaper to send in a sample to be tested.

Yeah I will buy for sure to check it before I send icp again.
Which copper test you suggest? Is salifert reliable or i have to buy the hanna?
What do you mean by rust kit? Is there different test for rust?