Never mix pool chemicals directly. Always pre-dissolve each chemical separately in fresh water and add to the pool at different times and locations.
Dangerous Combinations (NEVER Mix)
| Chemical A | Chemical B | Reaction Risk |
|---|---|---|
| Chlorine (any) | Muriatic acid | Chlorine gas — potentially lethal |
| Cal-hypo shock | Trichlor tablets | Fire and explosion risk |
| Cal-hypo shock | Dichlor shock | Fire and explosion risk |
| Chlorine | Algaecide (quat) | Foam and reduced effectiveness |
| Chlorine shock | Hydrogen peroxide | Violent reaction, fire risk |
| Potassium permanganate | Any chlorine | Violent reaction, fire risk |
Separation Requirements for Storage
| Category | Store Separate From | Notes |
|---|---|---|
| Chlorine products (any) | Acids (muriatic, dry acid) | Minimum 10 ft separation; separate locked containers |
| Chlorine products | Flammables, organics | Oxidiser — can ignite flammable materials |
| Acids | Bases (soda ash, bicarb) | Separate storage; neutralisation reaction |
| All pool chemicals | Food, household products | Dedicated, locked, ventilated storage |
| All pool chemicals | Heat sources and direct sunlight | Accelerates degradation |
Notes
- Always add chemicals to water, not water to chemicals.
- Wear eye protection and gloves when handling any pool chemical.
- Store chemicals in original containers with lids tightly sealed.
- Keep Material Safety Data Sheets (SDS) accessible for all stored chemicals.
Sources:
- Pool & Hot Tub Alliance — Pool & Spa Operator Handbook, 2022
- OSHA — Chemical Safety Standards