This actually makes me pretty happy. I’ve been having a problem in this tank for at least 6 months now and couldn’t figure out what it was. I thought I checked everything. This probe holder was in the back of my sump 2” above the waterline so I really never thought about checking it dumb me. It was only exposed to water 2 to 3 times a month when doing water changes. I have done a lot of testing and even triton test and could never find a problem.