What Hot Tub Chemicals Do I Need?

Struggling to keep your hot tub clean and safe? Without the right chemicals, your relaxing soak could turn into a breeding ground for bacteria. 

Cloudy water, bad smells, and skin irritation are just the beginning. But don’t worry, this post breaks down exactly what hot tub chemicals you need to keep things crystal clear and worry-free.

• Use a Sanitizer: Chlorine or bromine is essential to keep your hot tub water clean and bacteria-free.
  
  

• Balance pH and Alkalinity: Keep pH between 7.2–7.6 and alkalinity between 80–120 ppm.
  
  

• Shock Weekly: Use shock treatments regularly to break down contaminants and refresh the water.
  
  

• Clean and Maintain: Clean filters monthly and use clarifiers or enzymes to reduce foam and buildup.
  
  

• Store and Handle Safely: Test water often, follow dosing instructions, and store chemicals in a dry, secure place.

• Sanitiser Is a Must: Use chlorine, bromine, or oxygen to keep the water bacteria-free. Bromine is ideal for hot tubs.

• Maintain pH Balance: Ideal pH is between 7.2–7.6. Use soda ash to increase it, and sodium bisulfate to lower it.

• Control Alkalinity & Hardness: Use sodium bicarbonate to stabilise alkalinity. Adjust calcium levels to prevent cloudiness or scale.

• Give Shock Treatments: Regular shock (chlorine or non-chlorine) keeps the water fresh and clear.

• Remove Foam, Oils & Dirt: Clarifiers, enzymes, and defoamers help eliminate lotions, oils, and floating particles.

• Clean Filters & Plumbing: Use filters and plumbing cleaners to keep the system running smoothly and efficiently.

• Test and Store Chemicals Properly: Check water with test strips weekly. Store chemicals in a cool, dry, and safe place.

• Sanitizer (Chlorine or Bromine): Kills bacteria and keeps the water clean and safe to use.
  
  

• pH Increaser and Decreaser: Helps maintain the right pH balance to prevent irritation and protect your equipment.
  
  

• Alkalinity Increaser: Stabilizes pH levels and prevents sudden spikes or drops in water chemistry.
  
  

• Calcium Hardness Increaser: Prevents corrosion of metal parts and protects the hot tub shell from damage.
  
  

• Shock (Oxidizer): Breaks down contaminants and refreshes the water by removing buildup of oils, sweat, and residue.

• Balancing pH and Alkalinity: Your hot tub’s pH level should stay between 7.2 and 7.8, and alkalinity between 80 and 120 ppm. This balance keeps the water safe and prevents damage to your hot tub's internal components.

• Using the Right Sanitizer: Sanitizers kill bacteria in the water. You can use chlorine (1–3 ppm), bromine (3–5 ppm), or biguanide (30–50 ppm) depending on your personal preferences or skin sensitivities.

• Shocking the Water Weekly: Shock treatment provides a deep clean and boosts your sanitizer’s effectiveness. Use it once a week, or after heavy use, to keep the water fresh and clear.

• Monthly Filter Cleaning: Spray your filters with a cleaner and let them soak for 15 minutes every month. This helps maintain their performance and keeps your water crystal clear.

• Calcium Hardness Increaser (If Needed): If your local water is soft, use a calcium hardness increaser to protect your hot tub parts from corrosion and help balance your water more easily.

• Clarifier for Temporary Foam Removal: If you notice foam on the water’s surface, a clarifier can provide a quick, temporary fix. However, it's not a permanent solution—be sure to identify and address the root cause.

• Best Practices When Adding Chemicals: Always keep the cover open, run the jets, measure accurately, and follow instructions when adding chemicals. These habits ensure safe and effective water treatment.

Hot tub water should be tested at least twice a week, or daily if used often. For ideal water balance, check pH levels daily. 

Frequent testing is essential when using chlorine or bromine sanitizers, especially during heavy use, to maintain safety and prevent water imbalance.

Hot tub chemicals should be added regularly based on water testing and usage. Add sanitizer like chlorine or bromine after each use or as needed to maintain levels. 

Adjust pH and alkalinity one to two times monthly, or more often if tests show imbalances.

Wait at least 20 minutes between adding different hot tub chemicals to ensure each one fully dissolves and disperses. 

Keep the jets running during this time. After shocking the hot tub, wait a minimum of 12 hours before use to allow sanitizer levels to drop safely.

While hot tub chemicals are typically added to warm water, some can be safely added to cold water if pre-dissolved in a separate container.

Always follow the chemical’s specific instructions to ensure proper mixing and distribution, particularly with granular types, to maintain water safety and effectiveness.

Hot tub and pool chemicals are not interchangeable. Differences in water volume and chemical concentration require specific treatments for each. 

Using hot tub chemicals in a pool can lead to ineffective sanitation, equipment damage, and unsafe water conditions. Always use products designed for the intended system.

Yes, hot tub chemicals like chlorine and bromine can harm or kill grass if discharged in high concentrations. 

While they’re essential for water sanitation, these substances are toxic to plants. Avoid draining hot tub water directly onto lawns to prevent chemical damage to your grass.

To add chemicals to a hot tub, remove the cover, run the jets with air valves off, and add chemicals directly to the water. 

Wait 20 minutes between additions. Keep the cover off for off-gassing. Wear gloves, goggles, and a mask. Never mix chemicals beforehand.

• Choose the right spot: Store chemicals in a cool, dry, and well-ventilated area, away from sunlight and moisture.
  
  

• Keep original containers: Always use the original packaging with labels intact to know what each chemical is.
  
  

• Seal tightly: Make sure lids are closed tightly to avoid spills or contamination.
  
  

• Don't stack: Avoid stacking containers to prevent tipping or leaking.
  
  

• Separate chemicals: Never store chlorine and acids together—they can cause dangerous reactions.
  
  

• Keep away from kids and pets: Store chemicals in a locked cabinet or shed, out of reach.
  
  

• Follow instructions: Always read and follow the manufacturer’s guidelines for each chemical.

• Chlorine – Short-Term Sanitizer: Typically lasts 2–3 days before needing a top-up.
  
  

• Bromine – Long-Lasting Sanitizer: Remains effective for 4–7 days, especially in hot water.
  
  

• pH Increaser – Quick pH Booster: Works instantly but may need reapplying if pH drifts.
  
  

• pH Decreaser – Fast pH Reducer: Quickly lowers pH; how long it lasts depends on water use.
  
  

• Alkalinity Increaser – Stabilizes pH: Can last several days to weeks if water stays balanced.
  
  

• Calcium Increaser – Long-Term Hardness Control: Effects last until water is replaced or diluted.
  
  

• Shock Treatment – Deep Cleaner: Active for 1–2 days; ideal for weekly or post-heavy use.

Hot tub chemicals like chlorine and bromine are essential for sanitation but can be harmful if misused. 

High levels may cause skin irritation, dryness, burns, or respiratory issues. Proper handling and regular monitoring are crucial to balance safety and hygiene in hot tub maintenance.

To avoid hot tub chemical exposure, follow product instructions carefully, never mix chemicals, and ensure the area is well-ventilated when adding them. 

Always shower before and after using the hot tub, and regularly monitor and adjust chemical levels to maintain safe water conditions.