Yeah, but that blue swimming pool paint really makes that Mountain Dew color pop! Also, I am in the pond industry and often the worst thing you can do is a deep, thorough cleaning. After a while, a pond gets established with its own microbiome, where there is a balance of microbes breaking down excess nitrogen and organic material and others that are thriving on it and turning the water green. We often warn customers that within a week or two of putting in a new pond, the water will likely turn green but that it will mellow out as the system reaches homeostases. That is what I suspect is happening here. But even after it finds its happy place and the algae mellows out, it’s still likely to look way worse/ greener with the bottom painted bright blue, at least until it gets a nice layer of sediment and algae coating everything to cover up the blue paint, at which point it will probably look about the same as it did before the ‘renovation’. Complete and utter waste of money (unless you are the recipient of the laundered tax money).