Enter your pool volume, CYA, and current FC. We’ll calculate your target SLAM chlorine level and how much liquid chlorine to add.
Fill in your numbers, then hit Calculate. Your inputs are saved automatically on this device.
SLAM stands for Shock Level And Maintain. It is a controlled process for clearing algae and restoring water clarity by raising Free Chlorine, or FC, to a target based on the pool’s cyanuric acid level, then maintaining that target until the pool is clean.
SLAM is not one large chlorine dose. The chlorine is consumed as it attacks algae and other contaminants, so the pool must be tested and re-dosed repeatedly. The more often the target FC is restored, especially early in the process, the faster the cleanup usually goes.
Enter the pool volume, current CYA, current FC, and the percentage shown on the liquid-chlorine label. The calculator selects the matching SLAM target from the CYA table and estimates how much liquid chlorine is needed to reach that target.
Use an accurate pool volume and a dependable CYA test. A wrong CYA reading changes the target FC, while an incorrect pool volume changes the chemical dose.
The process is complete when the water is clear, combined chlorine is 0.5 ppm or lower, and the pool passes an overnight chlorine-loss test. Stopping as soon as the water looks better often allows algae to return.
Follow local guidance and your chemical labels. Many pool owners wait until the water is clear, the bottom is visible, and FC has returned to the normal operating range for the current CYA level.
Continuous circulation and filtration are usually helpful during active algae cleanup. Watch the filter pressure and clean or backwash when needed.
That usually means chlorine is still being consumed by algae or another contaminant. Continue testing and restoring the target until the chlorine demand is resolved.
No. A saltwater pool is still sanitized with chlorine. Liquid chlorine is commonly used during SLAM because the salt cell may not produce chlorine fast enough to reach and maintain the required level.
The fastest SLAM is the one you maintain. Test and re-dose as often as practical at the beginning instead of letting the chlorine fall for hours. The word that matters most is Maintain.