Zinc & Nickel too high! Suspects?

[Reef Puncher]

i had high levels of tin and zinc, it stumped me for months. found out there was a hidden piece of metal i couldnt see in my sump that was rusting. i saw another post where the guy had high levels and his rodi filters wasnt properly filtering it out, he changed his canisters and it fixed his problem. if your next icp comes back high, then maybe do a dig into the system to look for metal?