OK round one (first crash) Feb 2018
Cu 5.6 vs 0.1 "set point"
La 5.16 vs 0.1 "set point"
Zn 8.3 vs 4 "set point"
Li 1875 vs 200 "set point"
Round two (second crash) Dec 2019
Li 950 vs 200 "set point"
Si 190 vs 100 "set point"
The lanthanum in the first round I can account for (phosphate binder) and the heavy metal seemed to be from a piece of rock dissolving in my Ca reactor - which I managed to find with a magnet. Second go around the only thing I could think of was a piece of manmade shelf rock that I had added to the tank prior to the first crash so that is gone now. Also had high phosphate in the second round but not sure that is repeatable as I did not pick it up with a couple of new test kits (weird). Between the first and second episode, I changed my RO/DI water source, changed my primary salt source and stopped/replaced any additives (e.g. FUEL, trace elements, etc.) so none of those seem like a viable source.
Not sure this helps but interesting none the less...