After flushing, the water level in the bowl drops a bit. It takes about 30 seconds and loses between one and two inches. It starts dropping fairly fast, then slows, then stops, and then the level holds steady until next flush. Bowl still has a nice, respectable amount of water.
No other problems around toilet; no word from person downstairs about leaks or ceiling stains (but haven't had chance to ask them specifically since noticing this). I'm not sure if the floor's level; may slope slightly toward back of toilet, don't have a level handy.
This may even be normal for this toilet (is that likely/possible?)… I only noticed it now, about a week after clearing a clog with a closet auger, and hadn't paid attention to whether it dropped or not before.
About that clog: it was from a toothbrush dropped into the toilet and pushed further down when I tried to pull it out by hand. Auger didn't retrieve toothbrush, but I guess pushed it through to main drain, because toilet has flushed fine ever since.
Do any of these details make it more/less likely to be a leak into the subfloor? And if that is likely, I guess that makes things very urgent, or would it take a long time do any damage? (It'll be tricky to bring in a plumber until a few weeks hence, esp. if that means coordinating with other tenant.)
Apologies for full-on newb questions; this isn't so much DIY as should-I-have-someone-else-do-something, and how-panicked-should-I-be-if-at-all.
Best Answer
Open up the back part of your toilet and push down firmly on the flush valve ball (the flap that goes up and down when you press the toilet lever) after you flush the toilet. Your ball/flap probably is leaking a bit and eventually settles after a flush. These can be replaced by following a set of instructions and spending $15.