Summer Shield
Chlorine Extender

Once a Season


Sustain Summer Shield Chlorine Extender provides water with an extra level of protection against algae. It does this by creating a reserve, or backup, of chlorine fighting power that is released on-demand when routine sanitizing levels drop (below 1ppm), such as after a rainstorm or pool party. Sustain Summer Shield chlorine extender also contains a clarifier to gather suspended particles that can cloud your water, making them easier to be removed by the pool filter.

Summer Shield Chlorine Extender is a “good form” of combined chlorine. It is measured by subtracting the Free Available Chlorine (FAC) reading from the Total Chlorine (TA) reading. Proper application of the Sustain 3-Part system will prevent “bad” combined chlorine (weak, foul smelling water) from forming. So remember, what is measured as combined chlorine is actually the Summer Shield concentration in water when using the Sustain System.

  1. Ensure that the water being tested has been correctly Energized or shocked within the last 12-24 hours and that the water has had no heavy bather load since Energizing/shocking.
    1. 1 cup of Energizer per 5,000 gallons of pool water
  2. Test water for pH, TA, CH, CYA, FAC, and TC (and any other necessary parameters).
  3. Subtract FAC from TC to get CC (TC – FAC = CC)
    1. CC is the amount of Sustain® Summer Shield in the water sample.
    2. Maintain Summer Shield Extender between 1.5 and 5 ppm!

Used according to label directions, one dose will last all summer (150 days)*.

* Sustain Summer Shield levels can be affected by splash out and dilution (addition of water to the pool). To assure a proper Shield level, have your authorized Sustain dealer test your Shield level every six weeks. For Summer Shield Chlorine Extender to be effective, it must measure 1.5 ppm to 5 ppm.