[bncinwv]

We have never had a problem with the tanks in all three models. With that said, the gray tank is usually left open simply because with three women taking showers, I would be dumping multiple times a day which is not going to happen. I close it every couple of days to allow a surge after dumping the black tank. Black tank is dumped every other day, whether it needs it or not. Galley tank on new rig will stay open all the time since washer and dishwasher drain into it, that surge should prevent deposits from forming. On previous rigs it was on every other day schedule as well. I think the key may be that we do not fill the tanks to capacity ever and dump more frequently than is really needed. It seems to work for us, perhaps it worth considering adopting a more frequent dumping schedule? Just a thought from a rambling mind!
Bingo