Black mold on bathroom caulk is one of the most common bathroom problems. Most surface mold can be removed without replacing the caulk — but if the mold is deep inside, recaulking is the right move.
Apply mold remover gel directly onto the moldy caulk. Press paper towels on top to keep it in contact. Leave for 30-60 minutes.
Remove the paper towels and scrub firmly with a brush. Rinse thoroughly with clean water.
If mold is stained deep inside the caulk, strip the old caulk completely with a removal tool. Let dry for at least 24 hours. Apply fresh mold-resistant silicone caulk.
Run the exhaust fan during every shower and for 15 minutes after. Mold grows in moisture — dry air is your best prevention.