You can also buy deodorizers in liquid and powder form.
From the RV world there were two types, one was formaldehyde or other chemical based and the idea is to embalm it if you will, sterilize it so no bacteria can live, those were usually blue.
Then there is the biological approach, put lot of bacteria in that will help eliminate the odor
. They were usually green or orange.
Key was they do not mix, one sort of neutralizes the other, so pick one way and stick with that.
I didnít like the formaldehyde way myself, I assumed that was a chemical you donít want to turn loose into the environment
On the Boat
, I installed a 1Ē vent with the new tank, short run and all uphill and so now put no additives into the tank.