Hayward AquaRite Check Salt Light: What It Means and What to Test

What people ask with the Check Salt light on

Scoped to this one indicator on a Hayward system. Where the answer depends on whether the light is steady or flashing, it says so, because the manual treats those as different conditions.

Does the Check Salt light mean my cell is dead?

Usually not. Check Salt is a report about the salt level the controller believes it is seeing, and the level it believes is derived from the cell rather than measured in the water. Cold water, scale and weak flow all trip it with salt in range, which is why an independent water test comes before any spending.

Cleaning first, which costs almost nothing

Should I add salt when the Check Salt light comes on?

Not until a test that is not the controller agrees the water is low. Adding salt on the strength of the display alone is the most common way owners here spend money before they need to, and salt does not evaporate, so a pool that was in range last month has not quietly lost it.

Why does the light come on in cold water when nothing has changed?

Because the reading is a calculation, and water temperature is one of its inputs. A pool that reads correctly in August can trip the same indicator in October at an identical salt level. It is the single most misread behaviour on these systems.

What is the difference between steady and flashing?

The manual treats them as separate conditions rather than as degrees of the same one, so it is worth noting which you have before doing anything. Flashing and steady point at different next steps, and guessing between them is how people end up cleaning a cell that did not need it.

If cleaning does not fix it, what is the next thing to check?

Whether the controller and the cell disagree about the water at all. If an independent test says the salt is in range and the display still does not, the fault is in the cell or the sensing rather than the pool, and that is the point at which a replacement becomes the honest conversation.

When the display and the water disagree

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.

High Salt

HIGH SALT When illuminated, the salt level is too high and AquaRite has shut down.

Hayward AquaRite owner's manual, 092540 RevG

Flashing or steady? They are not the same

This state has not been checked against the manual yet. Steady: stopped. That is the state worth acting on. The numeric trip point for this state has not been checked yet.

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.

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.
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. Strips are quicker. A drop test is what settles an argument with a controller.

You need a number that does not come out of the box you are judging, and this step does not work without one.
Check current prices on salt test kits
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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
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.