I remember spraying Coil Cleaner in the Condenser Coils, then blasting them with combo of Air and Water. That stuff was an Acid if I remember, but no where near as strong as the ones used to clear UrinalsGot the new tach installed today, and started cleaning the pontoons. Since I’m in the HVAC trade I just used coil cleaner, it works wonders lol. Can’t figure out how to post pics or I would, keeps saying they are to big.