I'll try to make this short and sweet!!!! I've been living full time in my wonderful trailer for 3 months now due to losing my home in the Camp Fire in California. I'm quite comfortable and could possibly be calling this HOME for the next year. I'm hooked up to a septic tank, well water and electricity. I would like to know WHY the bathroom sink smells like a sewer? I have tried leaving all tanks open....or all tanks closed until 3/4 full. I flush out the system once a week. I've gotten to where I hold my breath when I run the bathroom sink faucet to brush my teeth. I've used vinegar and baking soda numerous times and have even put some of the black tank powder down the sink. Summer is just beginning and I don't want my trailer smelling like an outhouse.