Raritan C.P. is an outstanding sump cleaner
It's a bio-enzymatic cleaner that's marketed as a toilet bowl cleaner, but also happens to be the best sump and drain cleaner on the planet too....'cuz not only does it destry odor on contact, but the enzymes also "eat" hair, soap scum, grease, body oils and all the other things that go down drains. A few ounces squirted down the drain once a week when it can stand at least overnight will keep your sumps clean and odor free. (It does the same for toilet bowls, btw.)It's important that sumps (and bilges) ARE kept clean...because a wet dirty sump or bilge is a primordial soup that can make a boat smell like a swamp or even a sewer, especially once the weather gets hot. I get calls all the time from people who've torn out their whole sanitation system trying to get rid of what they thought water "head" odor, when all they really needed to do was clean their sumps and bilges.Jack, there's nothing wrong with your sump pump...like your bilge pump drain, the hose has an arch in it...what's in the hose between the top of the arch and pump runs back down when the pump shuts off. If you only want CLEAN water to be left sitting in your sump, run enough water down the shower drain to replace all the dirty water. Or...just use C.P. in it and don't worry about it.