My tank is relatively young and just had it first birthday in mid may. All my equipment was purchase new and what most would consider good quality, Kessil lights, Nyos Skimmer, MP40s and Varios DC return pump. I have complete drained the sump 3-4 times over that year, planning to do it again in a few days. I have also cleaned and completely dissembled every pump every few weeks/months with no signs of rust. I keep running Triton ICP every month which is expensive at $50 per test. Seems the Chromium color meter I ordered is on back order anyway so they canceled my order. At around $65 for the color meter it seemed to be solution for me to quickly get to the bottom of the source. I figured I could even strain my defrosted frozen food and test the chromium there as well as RODI and freshly mixed saltwater without spending a fortune on Triton ICP tests.