Do you ever get a film on top of newly mixed water? I had a foamy, brownish film and I ended up scooping it out. It could be the way I’m mixing the water, I suppose. I use a drill with a mixing attachment to swirl the water while I’m pouring the salt in. Once I have it to 1.026ish, then I turn the power head on and let it sit for a while. I usually end up using my water within a few hours after mixing it but this time, I let it sit overnight. The foamy film was gone the next day but there was still a shiny film. I had completely scrubbed the Brute can before filling it with RODI too, so I don’t think there was anything else in there. The power head is only a couple months old and the drill attachment has only ever been used for mixing water.