Black tank odor

Are you running an exhaust fan while you're in the shower? Is the toilet nearby with the lid open, perhaps?

It is not from grey tank. The odor is black tank. I poured a bunch of pine sol into black tank and that is the odor we got last time. I am not sure why it seems to happen when we are showering. We do run the vent fan when showering but not when toilet is in use. I am not getting any odor from grey tank

^^^^^ x2

Showering and strong odor from black tank.......:H

The 2 are not connected.

Shower drains to grey tank.
Could be 'stuff' in shower 'P' trap that is getting stirred up while using shower.
Could be the air admittance valve under bathroom sink that is getting pulled open while shower water is draining down to grey tank (grey tank odors can stick as bad as black tank)
Could be smelly Hot water while using shower........which would also smell when using any hot water.


Just don't think smell is from black tank while using shower (unless someone is using toilet at same time)

Might check your vent stack or vent valve to make sure they are working properly.

Hope this helps.