Salt water pool not generating chlorine
Salt falling under 2600 ppm (parts per million, the number a salt test shows) makes a Pentair IntelliChlor turn itself off. Water under 50 F makes a Hayward AquaRite stop. Work through the checks in this sequence: salt, water temperature, flow, the cell, then stabilizer.
Which check comes first?
- Start by testing salinity, since a Pentair IntelliChlor quits under 2600 ppm.
- Then look at water temperature, because anything under 50 F will stop a Hayward AquaRite.
- Test the flow rate, since the Pentair IntelliChlor Plus and the LT units require at least 25 GPM.
- Give the cell a look. Both Pentair and CircuPool put calcium hardness at 200 to 400 ppm.
- Check the stabilizer. The 30 to 50 ppm figure comes from Pentair, Jandy TruClear and CircuPool.
Low salt
Test the salt first. Per Pentair's installation guide, the IntelliChlor shows its low salt LED under 2800 ppm and powers down under 2600 ppm. The IntelliChlor Plus and LT tell you to add salt under 3000 ppm.
Pentair's salt range runs 3000 to 4500 ppm, and 3600 ppm is ideal. Salt under 2.0 gpl (grams per liter; 1 gpl is 1,000 ppm) makes a Jandy AquaPure switch its cell off. Salt that low kills the cell early, Jandy says.
Test before you pour in any bags. Hayward points out that partially draining and refilling with fresh water is the only fix for high salt.
Cold water
Some cells shut off in cold water. Hayward's product manual says water under 50 F stops an AquaRite and sets the Generating LED flashing.
Below 52 F, accurate within 3 F, Pentair's temperature sensor cuts the IntelliChlor off; in metric that's 11 C, within 1.67 C.
Flow
Some cells stay off when flow is low. Pentair's Plus and LT manual states the cell makes no chlorine until the flow sensor reads at least 25 GPM.
Under 25 GPM, those Pentair units keep the cell off.
Scale on the cell
Keep the water in range. Calcium hardness of 200 to 400 ppm and total alkalinity of 80 to 120 ppm appear in both Pentair and CircuPool's manual.
CircuPool also wants pH from 7.2 to 7.8. With a Jandy AquaPure, running salinity under 2.0 gpl wears the cell out early.
Not enough stabilizer
Your next test is cyanuric acid.
A level of 30 to 50 ppm is what Pentair, Jandy TruClear and CircuPool call for. An outdoor Hayward AquaRite 900 asks for the same. For indoor pools, the 900 calls for 0 ppm. Older AquaRite models need 60 to 80 ppm instead. Aim for 80.
The Jandy AquaPure runs on 50 to 75 ppm, rising to 75 to 85 ppm once water passes 30 C. Intex suggests stabilizer equal to 1% of the salt's weight, while CircuPool warns that readings over 50 ppm weaken your chlorine.
Questions people bring to the counter
What's keeping my IntelliChlor from making chlorine?
A Pentair IntelliChlor stops if salt falls under 2600 ppm or water drops under 52 F, give or take 3 F. The IntelliChlor Plus and LT also stop when the flow sensor reads under 25 GPM.
What's stopping my salt cell from making chlorine?
Low salt and cold water both set off automatic shutoffs. A Jandy AquaPure shuts off under 2.0 gpl of salt; a Hayward AquaRite stops under 50 F.
What's the way to boost free chlorine in a saltwater pool?
Put your salt and stabilizer in your manufacturer's range. Pentair advises keeping salt at 3000 to 4500 ppm, ideally 3600 ppm, along with cyanuric acid at 30 to 50 ppm.
How can you tell when a salt cell is wearing out?
Per Jandy, running salt under 2.0 gpl wears a cell out early. If salt ran that low, get your cell checked. Both Pentair and CircuPool set calcium hardness at 200 to 400 ppm.