Put a dozen or so drops of green food coloring in your tank to test for silent leaks. If the dye appears in the bowl you may need to change the ball or flapper, if no dye appears within a 15 minuet period your toilet is leak free.
Reliable Rooter & Plumbing, Inc.
2925 College Ave A12, Costa Mesa, CA 92626
949-673-5600 St. Lic. # 753331