i feel like i kinda had the same issue even after i had located my source of rust issues, it made me wonder if it binds to rocks or something?
it was a weird battle for me for sure, like i thought ok nice found the rusting thing, removed it, ran cuprisorb and a poly filter, i should be good. send icp in, still metals, wtf. buy detox, run it, new poly filter, send triton test, still metals
i think i was finally like fuck it and just put the cuprisorb in and did detox again, which was probably not the smartest thing in the world, but since i was losing everything anyway..
like people say if u run copper in a tank with rock and sand, the rock/sand absorbs the copper, so i feel like it kinda makes sense for it to absorb other metals too? maybe turkey basting the rocks and siphoning the sand helps too?