Method and apparatus of obtaining water conditioning utilizing localized hot zone

Disclosed is a method and an apparatus enabling water-conditioning processes to be performed using a heater initially equipped with an aquarium tank for the purpose of supplying heat. Instead of allowing heat to propagate globally, reactor housing is introduced in the tank enclosing the heater so as to form a localized hot zone. The temperatures of the hot zone are maintained at high degrees sufficient to initiate various water-conditioning processes with efficiency, including alga control, ammonia control, water-hardness control, and sterilization. The construction of the reactor housing is simple and inexpensive, and its geometry is compatible to a heater which can be purchased commercially. In short, multiple functions are added to a heater installed in an aquarium, performing water-conditioning processes in addition to the basic task of supplying heat, allowing water quality of the aquarium to be improved and maintained.