Water conditioning systems

A portable water conditioning system, comprising:

• a water conditioner having a plurality of conditioning stages configured to condition water, the plurality of conditioning stages comprising, in a direction of flow of the water through the water conditioner, a reverse osmosis stage and a deionizing stage;
• a first sensor configured to detect a first condition of the water before the reverse osmosis stage;
• a second sensor configured to detect a second condition of the water after the reverse osmosis stage;
• a third sensor configured to detect a third condition of the water after the deionization stage;
• a recirculation loop configured to recirculate a portion of the water exiting the reverse osmosis stage into the flow of water before the first sensor;
• and
• a controller in communication with the first, second, and third sensors, wherein the controller is configured to control the water conditioner to adjust a flow path of the water through the reverse osmosis and deionizing stages, based on the first, second, and third conditions, to provide conditioned water having a desired condition,
• wherein the controller is configured to determine a percent rejection of the reverse osmosis stage based on the first and second conditions when at least one variable affecting an accuracy of the determination of the percent rejection is at a known state, wherein the first and second conditions each comprise a level of total dissolved solids of the water.