Chlorine Granules vs. Chlorine Tablets: What’s Best for Your Hot Tub?

Spa Fuel
4 days ago
2 min read

Keeping your hot tub water clean, clear, and safe is essential — and that means using the right sanitiser. For most hot tub owners, that comes down to one big question: Should I use chlorine granules or chlorine tablets?

Both are effective at sanitising your spa, but they work in slightly different ways. Let’s break down the pros and cons of each so you can decide which is right for your setup.

What Are Chlorine Granules?

Chlorine granules are fast-dissolving, powdered chlorine that you manually add to your hot tub water.

✅ Pros of Chlorine Granules:

Fast-acting – Quickly raises chlorine levels, ideal for shock treatments or rapid response.
More control – You can fine-tune your dosage based on water volume and condition.
Dissolves quickly – No residue left behind if used correctly.
Great for occasional users – Perfect if you don’t use your spa daily and just want to sanitise before and after use.

❌ Cons of Chlorine Granules:

Manual dosing required – You’ll need to test your water more frequently and add chlorine as needed.
Not automated – No slow-release; needs regular attention.

What Are Chlorine Tablets?

Chlorine tablets are slow-dissolving, compressed chlorine that you place in a floating dispenser or inline feeder.

✅ Pros of Chlorine Tablets:

Slow-release – Provides a steady, consistent level of sanitiser over time.
Low-maintenance – Great for busy hot tub owners or holiday lets.
Convenient – Less frequent dosing required.

❌ Cons of Chlorine Tablets:

Slower to act – Not ideal for shock treatments or quick fixes.
Can lead to over-chlorination – If left too long in a small spa, chlorine levels can spike.
Can lower pH – Over time, tablets may acidify your water and require balancing.

So, Which One Should You Use?

That depends on how you use your hot tub:

For frequent, hands-on users: Chlorine granules offer more control and are great for regular testing and tweaking.
For hotels, rentals, or low-maintenance setups: Chlorine tablets provide a convenient, slow-dissolving option that keeps your water clean with less effort.