Just subscribed to this group so I apologize if this is widely known.

My toilet started flushing slowly. Floaters needed a couple flushes.
Hardly any vortex to speak of. Very weak flush.
It's a standard toilet maybe 50 years old.

First thought it might be a vent restriction, but rejected that.
Then I concluded that something was stuck in the loop.
Like a plastic handled hairbrush or a toy.
I snaked it numerous times but couldn't feel anything.
After enough nagging from my wife, I decided to just pull it and put
in a new one.
Sort of wanted to hammer it to pieces to see what was in there.
That's my destructive side.

But my son got in there first and noticed scale in the siphon jet
hole. That's the hole in the bottom fed by the tank.
He took a stubby screwdriver and coat hanger to the hole and scraped
out a load of scale.
Toilet works perfect since, with a strong vortex.
Surprised me.

The holes in the rim seem to flow water okay, so I suspect the siphon
jet got scaled up because there's always water sitting there.
Might be a good idea to vinegar clean toilets once in a while,
especially if you have hard water.
I'd turn off the water supply, empty the tank and soak out the bowl.
Then pour enough vinegar in the tank to flow through the rim holes
when flushed. Then add enough vinegar to the bowl to submerge the
siphon jet, and let it sit overnight.
Probably need a few bucks worth of vinegar.
That's what I'd do. But I have to find the time.

This is a pretty good vid of how toilets work.
I can't help the leading 15 second ad, so don't blame me.
http://videos.howstuffworks.com/scie...work-video.htm

--Vic