Isn't RODI water totally pure? As in absolutely nothing in it? Meaning PH would be 7.0 ? Which is totally neutral ?
I have a hard time seeing 1 fitting leaching so much copper

Totally neutral will increase it's ability to absorb ions. So yes, RO will pull Cu out quickly

+1 except ro/di water will pull more ions out not just ro water (I'm sure that is what you meant)

That is one of the downsides of di water it will quickly absorb any ions good or bad.

Brass on the upstream of the ro filter is fine, downstream, not so much.

No the pH of pure water is slightly acidic, hence why its called the universal solvent.

how long ago did you set up the ato? mine is about 4 mnths old and im really starting to worry at work. i know a couple more hours wont be the deciding factor but im just curious as to your timeline.

Its the same asd the posters. Its submerged in the fresh ro water as a reducer from the puump

pH of pure water is exactly 7.0, and neutral. The problem is that pure water is not usually pure. Exposure to air can form carbonic acid, making it slightly acidic.

sorry to hear of your crash! I recently had a minor one, due to kent carbon, unfortunately lost some livestock, and nearly killed off the live rock, my pod count was very low almost non existent. but After feeding the tank pods, and phytos (etc) its coming back hope everything turns out ok in the long run for you. its such a PITA when this happens

One guy at the LFS around here told me that the silicon would even absorb copper. Just like live rock and release it slowly back into the tank. I dojlno if it's true or not hope it helps.