We are careful not to allow greasy or fatty dishwashing water to enter our galley tank
Wipe off pots pans and dishes into the trash before washing them
Keep fat out of the tank that can go rancid helps allot
We treat our galley tank with this stuff
Add as
Directed and allow tank to come full before emptying
https://www.justscience.com/tanktech...tank-treatment
Hope this helps