If the Free Available Chlorine (FAC) level is either too high or too low, there are adjustments you can make. The same is true for pH levels.
Remember to use Test Strips or a DPD Test Kit when testing for FAC. Do not use an OTO Test Kit, which can cause FAC readings to appear erroneously high.
If Your FAC Level is Too Low (less than 1 ppm)
Low FAC levels are normal following a rainstorm or pool party. If FAC is less than 1 ppm, simply add Sustain Shock Treatment or apply your weekly dose of Sustain Shield Energizer Tablets to restore the chlorine level. If FAC remains consistently low, you will need to increase the 3-Inch Chlorination Tablet delivery. Use Sustain Shock Treatment or Sustain Shield Energizer Tablets to quickly re-establish the chlorine level, and make one or more of the following adjustments:
- Open or remove the 3-Inch Tablet adjustable skimmer dispenser lid.
- Use additional tablet dispensers if skimmer space is available.
- Increase your circulation time (minimum 12 hours per day)
- Increase the skimming (flow) action by opening the valve to the pump.
- Check your stabilizer level. It should be between 30-50 ppm. Low stabilizer can lead to rapid degradation of chlorine.
If you continue to have low FAC readings, take a water sample to your Authorized Sustain System Dealer. Your dealer will analyze your water, including a test for stabilizer, which might be low. Remember, as the weather gets hotter, increased amounts of chlorine will be needed to maintain proper chlorine levels.
If Your FAC Level is Too High (more than 3 ppm)
If a high FAC reading persists, you should decrease the 3-Inch Chlorination Tablet delivery by using the adjustable lid on the skimmer cup. The smaller the lid opening, the less the delivery.
If the tablet erosion is one tablet per week or less, and you still have high FAC readings, add one-half the normal dose of Shield Energizer tablets (½ cup per week for every 5,000 gallons of water.)
If you continue to have high readings, contact your Authorized Sustain System Dealer.If you continue to have high readings, contact your Authorized Sustain System Dealer.
If Your pH Level is Too Low (less than 7.2)
It is normal for the pH of the pool water to drop after a heavy rain, when using muriatic acid, or when using dry granular pH Down (sodium bisulfate). Unless the pH stays below 7.2 for more than 24 hours, don't worry about adjusting it, because use of the Sustain System tends to gradually increase pH. This is in contrast to stabilized white chlorine tablets, often referred to as trichlor, which lower the pH of the pool water, potentially causing damage to the pool surface and equipment. If the pH does remain low for more than 24 hours, use pH Up (soda ash/sodium carbonate) according to package instructions.
If Your pH Level is Too High (above 7.4)
To lower pH, use pH Down (dry granular sodium bisulfate) or muriatic acid, following dealer recommendations. The most effective way to reduce pH is to pre-dissolve sodium bisulfate granules or dilute muriatic acid in a bucket of pool water and, with the circulation system running, add it to the pool water gradually as you "walk" around the pool.