SALTCELLCHECK Find my model

The display reads zero, the test strip does not

A reading of zero next to a normal independent test almost never means the pool lost its salt. It means the system cannot take a measurement, and the brands measure in genuinely different ways.

Checked 63 manufacturer manuals on file Spot an error?

No Flow

NO FLOW When illuminated, the flow switch has detected no water flowing and the AquaRite has stopped generating chlorine. A flashing LED indicates a 15-60 second time delay period.

Hayward AquaRite owner's manual, 092540 RevG

Flashing or steady? They are not the same

Flashing: still running. This state is a warning, not a shutdown. Steady: stopped. That is the state worth acting on. The numeric trip point for this state has not been checked yet.

Check Salt

CHECK SALT When flashing, the salt level is low (below 2700 ppm) and AquaRite is generating at low efficiency. When illuminated steady, the salt level is too low and AquaRite has shut down. Before adding large quantities of salt, it is advisable to have your salt level professionally checked.

Hayward AquaRite owner's manual, 092540 RevG

Flashing or steady? They are not the same

Flashing: still running. This state is a warning, not a shutdown. Steady: stopped. That is the state worth acting on. The only numeric threshold Hayward publishes for this light is 2700 ppm, and it applies to the flashing warning rather than the shutdown.

A different light?

Then what

Two outcomes from here. If the reading came back fine and the light is still on, you are probably looking at scale rather than a dead cell, and cleaning costs almost nothing. If chlorine still does not recover after the salt is right and the cell has been cleaned, the plates are the problem and no amount of cleaning brings a worn coating back.

The sixty second test, before you spend anything

The controller's salt reading is a calculation, not a measurement. It is derived from how the cell is behaving, so a tired cell, cold water or low flow all move it. That is why the first real step is measuring the water yourself and comparing the two numbers.

  1. Take the sample from elbow depth, away from the returns

    Surface water and water sitting in front of a return jet are not representative. Elbow depth, mid-pool, in a clean container.

  2. Measure it with something that is not the controller

    A salt test strip or a drop test kit both give you an independent number. The point is only that the second reading does not come from the same box you are trying to judge.

  3. Compare it against what Hayward AquaRite says the level should be

    The ideal salt level is between 2700-3400 ppm (parts per million) with 3200 ppm being optimal.

    Hayward AquaRite owner's manual, checked 2026-07-25

  4. Read the two numbers together

    Water low and display low, in agreement, means the pool needs salt and the cell is reporting correctly. Water in range while the display reads low is the interesting case: the water is fine and the box is wrong about it, which points at the cell, the flow or the temperature rather than at your salt level. This controller's own published trip point is 2700 ppm, so a display reading under that with correct water is the reading worth acting on.

Adding salt on the strength of a controller reading alone is the most common way owners spend money in this category before they need to. Salt does not evaporate. If the water tests in range, the pool does not need any.