Optimizing efficiency of a water purification apparatus

A water purification apparatus comprising:

• a fluid circuit comprising:
• a reverse osmosis (RO) unit arranged to provide a permeate flow, and
• an electrically controlled deionization unit arranged downstream from the RO unit to receive at least part of the permeate flow;
• and
• a control arrangement comprising a control unit configured to perform the following operations:
• obtain, using a sensor, a current or voltage value indicative of power consumption by the electrically controlled deionization unit,
• determine whether the obtained current or voltage value meets at least one power consumption criterion, and
• control, using one or more valve units, recirculation of reject water produced by the water purification apparatus based on whether the obtained current or voltage value meets the at least one power consumption criterion, including at least one of (i) increasing the recirculation of reject water in response to a determination that the obtained current or voltage value indicative of power consumption is below a first threshold, or (ii) decreasing the recirculation of reject water in response to a determination that the obtained current or voltage value indicative of power consumption is above a second threshold.

A non-transitory, computer-readable medium storing instructions which, when executed by a processor of a water purification apparatus, cause the processor to:

• obtain, via a sensor, a current or voltage value indicative of power consumption by an electrically controlled deionization unit;
• determine whether the obtained current or voltage value meets at least one power consumption criterion;
• and
• control, using one or more valve units, recirculation of reject water produced by the water purification apparatus based on the determination, including increasing the recirculation of reject water in response to a determination that the obtained current or voltage value indicative of power consumption is below a first threshold or decreasing the recirculation of reject water in response to a determination that the obtained current or voltage value indicative of power consumption is above a second threshold.