Reading the lights on a Hayward AquaRite salt system
The AquaRite's panel tells you most of what's wrong. Here is what each light means, and what to check before you buy salt or a new cell.
The Hayward AquaRite is the salt system on more Conejo Valley pools than any other, and its front panel tells you most of what's wrong if you know how to read it. Here is what each light means and what to do before you buy anything.
Check salt, or low salt
The AquaRite doesn't measure salt directly. It measures how well the water conducts electricity through the cell and reads that as salt. Two things fool it. Cold water conducts less, so from about November to March the panel reads low even when the salt is fine. And a worn or scaled cell conducts less, which also looks like low salt.
So before adding salt, test the water. A salt test strip or a sample at a pool store gives you the real number. The AquaRite wants 2,700 to 3,400 ppm, with 3,200 as the target. If the test says the salt is fine and the panel says it isn't, the problem is the cell or the water temperature, and bags of salt won't help. They'll just leave you with a salty pool.
Inspect cell
This one isn't a fault. The system turns it on every 500 hours of operation as a reminder. Pull the cell and look through it. White crust on the plates is calcium scale, which is normal in our hard water and comes off with a diluted muriatic acid soak. Pour acid into water, never the other way, soak until the foaming stops, rinse and reinstall. If the plates are clean, put it back. Hold the diagnostic button for about three seconds to clear the light.
Scale left on the plates makes the cell work harder and shortens its life, so cleaning every three months is a good habit here.
No flow
The cell only makes chlorine when the flow switch confirms water is moving. If the light is on with the pump running, check the filter pressure first. A dirty filter, a closed valve or air in the line drops flow below what the switch wants. If flow is fine, the switch paddle may be stuck or the switch has failed. Either way, no chlorine is being made until it's fixed, and the pool will show it within a week in summer.
High salt
Usually the result of adding salt for a low salt light that was really a cold-water or worn-cell reading. The only fix is to drain some water and refill. Test first, add later.
The cell itself
A T-Cell-15 is rated for about 10,000 hours, which works out to three to five years at normal run times, less when scale is left on the plates. The diagnostic display shows the cell's voltage and amperage, and a cell drawing low current with the salt at the right level is a cell that's wearing out. A tech can tell from those numbers whether you need a new cell or just a cleaning.
One more thing: stabilizer
A salt pool with no chlorine reading and a healthy cell often has a stabilizer problem. Hayward recommends cyanuric acid between 60 and 80 ppm for salt pools. Too little and the sun burns off chlorine as fast as the cell makes it. Years of tablets before the salt conversion can push it well past 100, where the chlorine is there but tied up. A partial drain is the only fix for that.