What can you do? You can ideally begin by determining if the system or tank really leaks. Locating where the leak is coming from can help you take appropriate measures to eliminate the problem. This can easily be done by using a couple drops of food coloring and letting it sit inside the tank for an hour, making sure that the toilet isn’t used or flushed at this time. If you can see colored fluid or water on the floor, begin searching for the leak source. The source can be from the valve, the site where the supply tube connects, the area where the tank connects to the bowl, between the base of the toilet and the floor surface and so on. Wherever the source, you have the locate it and apply necessary mending. For loose tank bolts, you need to replace and tighten them. For a leaky supply tube connection, install a new supply line. For a cracked toilet tank, it may have to be replaced depending on the extent of the damaged. However, for some repairs that you can’t handle yourself because of its challenging nature, you need to stop using the toilet as well as letting a toilet repair team or a plumber step in and fix the whole system for you.