Mustard Algae Target Calculator

Understanding Mustard Algae Shock Levels

Mustard algae is a chlorine-resistant form of algae that often appears as a yellow or brown dust on pool walls, steps, ladders, and shady areas. Unlike ordinary green algae, it can survive at normal shock levels and usually requires a temporary increase in free chlorine after completing the normal SLAM Process.

How This Calculator Works

This calculator estimates a mustard algae treatment level using approximately 60% of your cyanuric acid (CYA) level. This elevated free chlorine level is typically held for about 24 hours after your pool has already passed the standard SLAM Process.

Before Raising Chlorine

• Complete the normal SLAM Process first.
• Pass the Overnight Chlorine Loss Test (OCLT).
• Water should be completely clear.
• Combined Chlorine should be 0.5 ppm or less.

During Treatment

• Brush the entire pool thoroughly.
• Place pool toys, ladders, poles, brushes, and cleaners into the treated water.
• Run the pump continuously.
• Retest chlorine frequently.