toresolve your flapper problem replace the flapper in the tank. You need to remove all the water in the tank shut off the water supply anf unscrew the 2 screws in the tank bottom and remove it from the toilet. then loosen the flapper and replace (local hardware store) and replace it. make sure you replace the gasket that connects the toilet and tank. put things back in order of which you took apart. I did this 2 weeeks ago and my stupidity it took all day instead of the 1/2 hr it should have. Good luck!