Wondering how to keep your inflatable hot tub clean? Having the right routine and using the best chemicals will help. What hot tub chemicals do I need? Follow these simple steps to ensure you're always soaking in sparkling clean water!

Quick Reference: Ideal Water Chemistry Levels

Before diving into the steps, here's a handy summary of the target levels you should always aim for:

• Chlorine: 3–5 ppm
• pH: 7.2–7.8
• Total Alkalinity: 80–120 ppm

Keeping all three in balance is the key to safe, clear, and comfortable water. If one is off, it can affect the others — so always test in this order: alkalinity first, then pH, then chlorine.

Step One: Add Chlorine Granules

To avoid a tub full of green algae, you must add Chlorine Granules to your water. This chemical works to sanitize and keep your water clean. The most ideal chlorine level is between 3-5 ppm. If the chlorine level is below 3, you should add more chlorine granules to your water. You can test your spa's chlorine level with our 3-in-1 Test Strips.

How much chlorine should I add to my Hot Tub?

Generally, to chlorinate your water, you will need to add approximately 3g of granules for each part per million.

• For a 4 Person Hot Tub add 6g / 0.2 oz (¾ tsp) at setup. To keep your chlorine level maintained, add a further 1.5g / 0.05 oz (just under ¼ tsp) each day.
• For a 6 Person Hot Tub add 8g / 0.3 oz (1 tsp) at setup. To keep your chlorine level maintained, add a further 2g / 0.07 oz (¼ tsp) each day.

How do I safely add Chlorine to my Hot Tub?

• Fill a clean plastic bucket with warm water and dissolve the correct amount of granules. Stir until completely dissolved.
• Turn on your spa circulation pump and pour the bucket contents into the spa water.
• Leave the pump running for 20 minutes.
• After 20 minutes, test your spa water with a Testing Strip. If the chlorine level is still too low, repeat the previous three steps.
• Wait another 20 minutes before using your hot tub.

Algaecide can be added alongside chlorine to prevent the growth of algae further.

Shock Dosing: When and Why to Shock Your Hot Tub

Shock dosing (also called superchlorination) involves adding a higher-than-normal dose of chlorine to rapidly sanitize the water. You should shock your hot tub:

• When you first fill it with fresh water
• After heavy use or a large number of bathers
• If the water looks cloudy or has an unpleasant odour
• Once a week as part of your regular maintenance routine

To shock dose, add approximately double your normal chlorine amount, run the pump for 20 minutes, and do not enter the spa until chlorine levels have returned to the safe range of 3–5 ppm. Always test before bathing.

Step Two: Test the pH Level

You will also need to use your 3-in-1 Water Test Strips for this next step. Simply dip the test strip into your water, shake off the excess and compare the colour to the chart provided. You should test the water at least twice a week and always just before you use your spa. An inflatable hot tub's pH level should be between 7.2 and 7.8. To correct your pH level, add the appropriate chemicals:

• pH Reducer — if pH is above 7.8
• pH Increaser — if pH is below 7.2

Why does pH matter?

If your pH is too high, chlorine becomes less effective and the water can become cloudy. If it's too low, the water becomes acidic, which can irritate skin and eyes and may damage your spa's components over time. Keeping pH in range ensures your sanitiser works properly and your soak is comfortable.

How much pH Reducer / Increaser should I add?

Add 10g / 3.5 oz of pH reducer or increaser per 1,000 litres of water.

How do I safely add pH Reducer / Increaser to my hot tub?

• Fill a clean plastic bucket with warm water and add the correct amount of pH Reducer / Increaser.
• Turn on your spa circulation pump and pour the bucket contents into the spa water.
• Leave the pump running for 20 minutes.
• After 20 minutes, test your spa water. If the pH level isn't between 7.2 and 7.8, repeat until the correct level is reached.
• Wait another 20 minutes before using your hot tub.

Step Three: Test the Alkalinity Level

As well as testing pH levels, you should also check your spa's alkalinity levels using the 3-in-1 Water Test Strips. You should test the water at least twice a week and always just before you use your spa. An inflatable hot tub's total alkalinity level should be between 80 and 120 ppm. To correct your alkalinity level, add the appropriate chemicals:

• Alkalinity Increaser — if alkalinity is below 80 ppm
• pH Reducer — if alkalinity is above 120 ppm

Why does alkalinity matter?

Total alkalinity acts as a buffer for your pH level — it helps prevent sudden pH swings that can make the water uncomfortable or reduce the effectiveness of your sanitiser. Always correct alkalinity before adjusting pH, as getting alkalinity right first makes pH much easier to balance.

How do I safely add Alkalinity Increaser to my hot tub?

• Fill a clean plastic bucket with warm water and add the correct amount of Alkalinity Increaser (1.5–2 tsp).
• Turn on your spa circulation pump and pour the bucket contents into the spa water.
• Leave the pump running for 20 minutes.
• After 20 minutes, test your spa water. If the alkalinity level isn't between 80 and 120 ppm, repeat until the correct level is reached.
• Wait another 20 minutes before using your hot tub.

Step Four: Remove and Prevent Foam

Foam (caused by soaps, detergents, oils and cosmetics) can sometimes build up in your spa. Excessive foam should always be removed using 'No Foam'.

What causes foam in a hot tub?

The most common causes of foam are:

• Body lotions, oils, and cosmetics
• Residue from swimwear washed with detergent
• Shampoo or soap not fully rinsed off before entering
• Low calcium hardness in the water

The best prevention is to shower before entering your spa and avoid using swimwear that has been washed with fabric softener or detergent.

How do I add No Foam to my hot tub?

• Shake the No Foam bottle before use.
• Turn on your spa circulation pump and pour the correct dose into your water (10ml–20ml).
• Leave the pump running for 20 minutes.
• After 20 minutes, if the foam has not completely disappeared, repeat the previous three steps.
• Add a further 25ml per week to keep foam at bay.
• We recommend showering before entering your spa.

Troubleshooting Common Water Problems

Even with a good routine, you may occasionally notice issues with your water. Here's what they usually mean and how to fix them:

• Cloudy water: Usually caused by low chlorine, high pH, or high alkalinity. Test all three levels and correct as needed. Shock dosing often resolves this quickly.
• Green water: A sign of algae growth, typically caused by very low or zero chlorine. Shock dose immediately and add Algaecide.
• Strong chlorine smell: Counterintuitively, a strong smell often means chlorine levels are too low, not too high. The odour comes from chloramines (used-up chlorine). Shock dose to break these down.
• Skin or eye irritation: Usually caused by pH being too low (acidic water). Test and adjust pH to the 7.2–7.8 range.
• Foamy water: Caused by soaps, oils, or cosmetics. Use No Foam and encourage bathers to shower beforehand.

Recommended Maintenance Schedule

Staying on top of your hot tub chemistry is much easier with a regular routine. Here's a simple schedule to follow:

• Daily: Add your maintenance dose of chlorine granules.
• 2–3 times per week: Test chlorine, pH, and alkalinity with your 3-in-1 Test Strips. Adjust as needed.
• Weekly: Shock dose your spa. Add 25ml of No Foam as a preventative measure.
• Every 4 weeks: Drain, clean, and refill your hot tub. Wipe down surfaces with mild soap and water — never use bleach or abrasive scrubbers.

If you keep on top of your water chemistry, you may be able to extend the time between full water changes beyond four weeks, saving water and money.

Additional Safety Information:

• Before you add any water treatment chemicals to your spa, please read the instructions on the label.
• Do not add chemicals to your spa when it is occupied by anyone.
• Only add chemicals to your spa when water is being circulated.
• Only add dissolved chemicals to your spa.
• Do not mix chemicals together — some can explode or create poisonous gases if combined. Water treatment chemicals are highly concentrated.
• Handle water treatment chemicals carefully in a well-ventilated area and wash your hands thoroughly afterwards.
• Store chemicals in a cool, dry, secure area — well out of the reach of children.
• Always use correct spa products when cleaning areas around your hot tub. Do not use household cleaners as they can contain phosphates that allow algae to grow. Do not use household detergents as they can cause foaming.
• Wave Spa produces an exclusive range of Wave Spa chemicals that can also be used on any other make of hot tub.

Regularly following this routine will keep your inflatable hot tub running better for longer and will save on your water bill. It is recommended to drain and refill your tub every four weeks, but if your water is kept clean, you may not need to drain it as often. When the water is drained, surfaces can be wiped with mild soap and water. (Do not use harsh chemicals like bleach, or scrub brushes that can damage the inflatable hot tub.)