Rob
Senior Member
When I drain my holding tank via vacuum pump out or simply by pumping out it appears that I always have about an inch and a half of stain or sludge in the bottom. My tank is made of poly, so you can shine a flash light thru the top and see the level. We have been full time live aboard for the past year, so it’s obviously had some exercise thru the tank! There doesn’t appear to be any extra foul odors venting out! I add the normal holding tank chemicals but this stain/sludge level never seems to change. Is there some extra strong cleaner that I can add and allow to slosh around while on rough water to do some scrubbing for me. How would driveway moss and mildew cleaner work, or bleach outdoor cleaner. The boat is a 1983 Kadey Krogen 42.