Find a LeakUse these toilet leak tablets to find out if you have a leak in your toilet. How they workThese handy dandy toilet leak tables work like this: Remove tank cover. Drop tablet in tank. Wait several minutes. If color appears in the bowl – you have a leak. Voila! NontoxicThe tablets are nontoxic and non-carcinogenic. The directions are easy to follow and they come in a moisture resistant package.