I would try running fresh water through everything and see if the problem solves itself.
I think if there are contaminates in your recycled water, they may be leaching into your marble around the seals.
Just a thought.
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Omni Cubed Larry
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..... that has been run on one of my 2 CNCs. ......
Put one of the pods from the machine that produced the stained stone on the other machine that didn't produce stains, and see if it behaves the same. If there is no stain, then it is a water problem (in the other machine). If it stains, then it is a pod problem.
You said you have some challenges with your water-treatment system. Are you running the same mixture of treated and city water through both machines? Why would one machine behave differently? Maybe answering that question will solve the mystery.
I had another thought. Black rubber cleaned with acetone will slowly break down and will usually leave black stains. Some chemicals in rubber compounds can leave yellowish stains when it reacts with other chemicals. I doubt it, but the seals could be reacting with some new chemical in the water.
Or, you cleaned the pods with something that the rubber didn't like. I have no idea what the ADI or CMS seals are made of. Or the stone has some different resin on it that is reacting with the rubber.
I'm not a chemist, but this stuff can be fascinating AND really weird sometimes. I hope you can get to the bottom of this quickly.
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