Just a thought to share, on an older RV I owned I thought I got a tank of stinky water and it turned out the smell was coming from the drain. If you are not sure, I would pour a Brandy snifter (or just a glass
) about half full of water, take it away from the sink and smell test the water again. Certainly you may have stinky water, but it is worth the test imo, and if the water is stinky, then sanitizing the system is in order, otherwise you need to treat the grey tank and drains. ~CA