However, in the swimming pool and swim spa tub industry, the most important function of baking soda is adjusting total alkalinity. Many users confuse baking soda with products that raise pH levels, but they are not entirely the same.

From a routine maintenance perspective: most swim spa tubs need a shock agent, not an algaecide. This is because the main problem faced by swim spa tubs is not algae, but the accumulation of organic pollutants.

In most cases, a swim spa tub requires a chlorine replenishment daily or every 1 to 3 days, ideally accompanied by regular testing of the residual chlorine levels in the water. However, underlying this conclusion are several prerequisites that must be understood.

The interior of a swim spa tub typically features: • Circulation intake ports • Filter intake ports • Current-generating system intake ports The rule of thumb is very clear: All intake ports must be completely submerged—covered by the water—with a certain margin of water sitting above them.

For most swim spa tubs, the ideal residual chlorine concentration is typically maintained within the range of 1.0 to 3.0 ppm (mg/L). • Below 1.0 ppm: Insufficient disinfection effectiveness • 1.0 – 3.0 ppm: Safe, effective, and comfortable • Above 3.0 ppm: May cause irritation and discomfort

In a swim spa tub, whether or not shock sanitization leads to a drop in pH depends on several key factors: •The type of sanitizer used •The dosage applied •The water's initial alkalinity level •The organic matter content in the water