I did a repair on the toilet that leaks. Now it leaks even more when flush. The leak comes from tank to bowl gasket. I believe I need to replace the gasket, but I can't find it in any of the hardware stores. The toilet is Karat Niagara. The opening to the tank is rectangle in shape. I don't think the circular gaskets that I found in Home Depot or Lowes will work. Any suggestion on where I can find rectangular tank to bowl gasket?
