Abstract: An additive product dispensing apparatus for a toilet tank which prevents waste of excessive chemicals within the toilet tank and causes the treatment solution to remain in the toilet bowl water after the flushing cycle. The dispensing apparatus includes a product chamber for receiving the additive product. The product chamber communicates with an overflow pipe of the toilet tank by way of a conduit assembly having three ball check valves associated therewith. The check valves allow dispensing of a specific dosage of the product and are responsive to the rise and fall of water in the tank.