Originally Posted by Vritang
Fowl odor from toilet water, may be septic?
This only happens in one of the upstairs bathrooms.
When I flush this toilet I sometimes smell a nasty odor.
The downstairs toilet and the otherupstairs toilet don't do this.
We use Clorox chlorine bleach tablets made for toilets in both of our toilet tanks. When either toilet is flushed, I can smell the fresh chlorine from the tank. After a while, the smell goes away.
Using that as an analogy, it sounds like your odor is in the water in the tank. If you remove the cover from the tank, can you smell the odor in the tank just before flushing?
If so, maybe try a Clorox chlorine bleach tablet in the tank. It might kill any bacteria that is living in the tank. Cheap enough to try and it helps to keep the toilet bowl clean. If it's not the problem, at least you'll have a clean looking bowl for a while.