I just noticed a brown stain developing around the niche for my floodlight. It's got to be new in the last couple weeks since I'm sure it was not there when I was chasing after my pool leak.
For sure though we have changed things... this is the first two weeks we've been using the SWCG and we are still learning about how to dial in both ph and FC levels. Tomorrow I'll get the underwater camera out and get the latest water sample test results. For now... any likely suspects? I'm guessing the seal around the niche is not good and this is an iron stain from the rebar around it... but I've never done this before so that is a pure guess.