Hot Tub Chemicals 101 – What Chemicals You Need and Why
We know how important your hot tub is to your wellbeing – whether it’s a long soak after a coastal walk, a must-have for health related issues, or a Sunday morning relaxation ritual – but keeping your hot tub in top condition takes more than just switching it on and sinking in. Hot tub chemicals are a must in order to keep your hot tub water clean and safe.
At South West Spas we specialise in hot tub repairs and servicing across Devon and Somerset. Our customers often ask for advice about chemicals, so here’s a simple guide to chemicals for a hot tub, why they matter, and how to keep your spa clean, safe, and ready to enjoy all year round.
Why are hot tub chemicals important?
Let’s start with the basics. Hot tubs are warm, moist environments, making them perfect for relaxation, but unfortunately also ideal for bacteria and algae if they’re not properly maintained. Without the right chemicals, your hot tub can quickly turn from spa to science experiment!
Using the right hot tub chemicals helps to:
- Kill bacteria and harmful organisms
- Balance pH and alkalinity levels
- Prevent scale, foam, and cloudy water
- Extend the life of your hot tub equipment
- Keep water clear, clean, and safe for you and your family
Hot tub chemicals
Here’s a quick breakdown of the key chemicals for a hot tub and what they do:
– Sanitiser (Chlorine or Bromine)
Your first line of defence. Sanitisers kill bacteria and keep your water safe. Chlorine is the most common choice and works quickly, but bromine is gentler on the skin and better for people with sensitivities.
Always maintain the recommended levels – too little won’t clean the water, too much can irritate skin and damage hot tub parts, including blistering the shell.
– pH increaser and decreaser
pH levels affect how comfortable the water feels and how well your sanitiser works. Ideally, your pH should sit between 7.2 and 7.6. If it’s too high or low, you’ll need to use a pH increaser or decreaser to bring things back into balance.
– Alkalinity increaser
Alkalinity acts as a buffer for pH levels. If alkalinity is too low, your pH can swing dramatically, making maintenance tricky. Keeping alkalinity in check stabilises your water chemistry and helps prevent cloudy or corrosive water.
– Shock treatments
Even with a good sanitiser, organic matter like body oils, lotions, and sweat can build up. Weekly shock treatments (oxidisers) break down these contaminants and restore sparkle to your water.
Use non-chlorine shock if you use bromine as a sanitiser.
– Anti-foam and clarifier
If your water starts to look a bit murky or foamy, a clarifier or anti-foam can help. These aren’t everyday essentials, but are useful additions to have on hand for when your water needs a quick refresh.
Maintaining your hot tub
We recommend testing your water at least 2–3 times per week with test strips or a digital tester. Staying on top of chemical levels helps avoid bigger issues and the need for hot tub repairs.
If you’re unsure or need help, we offer regular servicing and advice on water balancing checks and hot tub chemicals.
Using the right hot tub chemicals is essential for water hygiene and the long-term health of your hot tub. While it may feel a little overwhelming at first, a simple routine and the right products will keep your hot tub in great shape, so you can continue to enjoy it.
