Water treatment system

A dispensing device for dispensing a controlled amount of a chemical into a water container, such as e.g. a pool or spa, comprising:

• a pressure sensing device arranged to sense pressure variations in water contained by said container,
• a dispensing device coupled to said water container for dispensing a controlled amount of a water treatment chemical into said water,
• a processing unit having an input connected to said pressure sensing device, said processing unit being adapted for generating an output signal to said dispensing device, where said signal depends on the said pressure input signal, so that the dispensed amount of chemical is made to depend on the sensed pressure variations.

A method of maintaining the quality of water in a container, the method comprising the steps of

• detecting pressure variations in the water in the container due to the activity of people present in the container by the use of a pressure sensing device,
• generating a pressure variation dependent output signal using a processing unit taking as an input an output of said pressure sensing device,
• transferring said output signal to a controllable dispensing device adapted and arranged for dispensing a chemical into said water in dependence on said generated signal, whereby the amount of dispensed chemical is made to depend on the activity of people using the container.