One of the most prevalent problems with flush tanks is silent leaks. A slow, constant leak can waste hundreds of liters of water per month, increasing your water bill and putting stress on your plumbing system. To test for leaks, put several drops of food colouring into the tank. https://tourghananow.blogspot.com/2013/10/the-black-star-square.html?showComment=1759751907396#c8953999027417342134