I'd bet real money that your sanitation hoses are
at least one of the sources of your odor. Any other source is most likely to be bilges and/or sumps in desperate need of a REAL cleaning--lots of detergent and water, followed by flushing all the dirty water out, instead of just dumping in more cleaner and/or bleach and letting the bilge pump drain the "sink" (think about it...would that work in a sinkful of dirty dishwater? Then why would anyone think that would leave you with a clean bilge???) In most cases, if the source is the sanitation hoses, the odor is unique—a sharp, sour, only somewhat sewer-like odor that’s a result of the interaction between the waste and the hose material. (If your boat smells like a swamp or has very definite sewer odor, you may or may not have permeated sanitation hoses too...it only means that hoses are not the only source of your odor problem.) Because odors are always strongest at their source, the odor is strongest in the areas the hoses pass through, under, or behind. If you’re still in any doubt after poking your nose into all the places the hoses go, there’s a simple test that’s never wrong: clean off the outside of a section of hose where the odor is the strongest (this is to remove any odors from another source that may have attached themselves to the outside of the hose). Wet a clean rag in hot water, wring it out and wrap it around the hose. When the rag has cooled, remove it and smell it. If you can’t smell anything on the rag, that hose is not the source of your odor problem. But if you can smell the same odor on the rag, that hose has become permeated, and once a hose has become permeated with odor, it cannot be reversed; replacing the hose is the only cure. A few words about ozone generators: Ozone in any concentration strong enough to do any good is not only a health hazard, it's also HIGHLY corrosive and destructive rubber, neoprene and flexible PVC—in other words, every seal, valve and hose on a boat. According to the EPA, “Available scientific evidence shows that, at concentrations that do not exceed public health standards, ozone is generally ineffective in controlling indoor air pollution. The concentration of ozone would have to greatly exceed health standards to be effective in removing most indoor air contaminants. In the process of reacting with chemicals indoors, ozone can produce other chemicals that can be irritating and corrosive.” As for how well the portable ozone generators work when it comes to getting rid of odors… yes, people who’ve bought them rave do about how well they work. And, yes, the manufacturers do assure you that the ozone concentration is well below that which can present any health hazard. But if that's true, they can't deliver enough ozone to destroy the sources of any odors. If they did deliver enough ozone to destroy the sources of odors, it should only be necessary to run one occasionally. But among all the people you know who’ve bought ozone generators, have you ever met anyone who has one who's ever been able to turn if off without having odors return? That should be enough to tell you that ozone generators are only very expensive air fresheners, because they don't deliver enough ozone to be anything else. Save your money and get rid of the SOURCES of your odors. Eliminating the source is the only thing that really works. (Most of the above are excerpts from the link below).
