Disinfection and Sanitizers Flashcards

Which chlorine product has the highest available chlorine content by percentage?

Answer: Trichlor (trichloroisocyanuric acid)

Trichlor tablets contain approximately 90% available chlorine, the highest of all common pool sanitizers.

What is the most effective disinfecting form of free chlorine in pool water?

Answer: Hypochlorous acid (HOCl)

Hypochlorous acid (HOCl) is the active, uncharged form of chlorine that penetrates cell walls and kills microorganisms most effectively.

Trichlor and dichlor are considered 'stabilized' chlorines because they contain:

Answer: Cyanuric acid (CYA)

Stabilized chlorines contain cyanuric acid, which binds to chlorine and protects it from UV breakdown in sunlight.

What effect does sodium hypochlorite (liquid chlorine) have on pool pH?

Answer: Raises pH due to its highly alkaline nature

Sodium hypochlorite has a pH of 10–13, so adding it to pool water raises the pH over time.

Which calcium-based chlorine product will gradually increase total calcium hardness in pool water?

Answer: Calcium hypochlorite (cal hypo)

Calcium hypochlorite releases calcium ions each time it dissolves, progressively raising calcium hardness levels.

Why must calcium hypochlorite (cal hypo) and trichlor NEVER be mixed or stored together?

Answer: The combination can cause a violent fire or explosion

Mixing cal hypo (oxidizer) with trichlor (acid) triggers a violent exothermic reaction that can cause fire, explosion, and toxic gas release.

What is the recommended free chlorine range for a commercial swimming pool under the Model Aquatic Health Code?

Answer: 1.0–5.0 ppm

The MAHC recommends maintaining free chlorine between 1.0 and 5.0 ppm in commercial pools to ensure effective disinfection.