A ballast tank circulation system having inlet and outlet piping and means for adding one or more halogens in controlled amounts to the water within the ballast tank. One or more eductors are positioned within the ballast tank to mix and circulate water within the ballast tank. A recirculating pump is located externally to the ballast tank to ingest water from the ballast tank and discharge a stream of pressurized water. The recirculating pump receives water from the ballast tank through an inlet line that taps into the outlet piping from the ballast tank. An outlet line transport the pressurized water to the ballast tank. The eductor draws in the pressurized water entering the ballast tank and emits a high pressure jet of water that circulates within the ballast tank thereby circulating the chemical content of the ballast water. Test streams of water from the ballast tank can be analyzed to determine the level of at least one of halogens in the test stream to provide a halogen content signal. A controller receives the signal and compares the signal to a set point indicative of the level of halogen desired within the ballast tank to maintain, increase, or decrease the amount of chemical added to the water within the ballast tank in controlled amounts.