Yes, baking soda can be good for your hot tub, but only when your water actually needs it. It’s most commonly used to raise total alkalinity, but it can also increase your water’s pH in the right situation.

Here’s what to know about why people use baking soda in a hot tub, how much to add, and how long to wait afterward.

Why Do People Add Baking Soda to Hot Tubs?

The main reason people add baking soda to a hot tub is to raise total alkalinity, which helps keep your water balanced and prevents pH from swinging too far in either direction. When alkalinity is too low in particular, the water can become harder to manage, which can lead to cloudy water, unstable readings, and more wear on your hot tub over time.

Baking soda can also raise pH, though usually not as dramatically. That means if both your alkalinity and pH are low, it may help improve both at the same time. 

That said, if alkalinity is already where it should be, adding baking soda just to raise pH can create a different imbalance. That’s why it’s important to test your water first and make sure low alkalinity is actually the issue.

Why baking soda?

Baking soda is a practical option because it’s sodium bicarbonate, which is the same active ingredient used in many alkalinity increasers for hot tubs and spas. So if your test strip or liquid test kit shows low total alkalinity, baking soda can be a simple way to bring that level back into range.

How to Add Baking Soda to a Hot Tub

If your total alkalinity is low, adding baking soda is pretty simple. The important part is doing it gradually instead of dumping too much at once.

Here’s a quick guide on how to add baking soda to a hot tub:

1. Test your water first. Check total alkalinity and pH before adding anything. You want to make sure baking soda is actually the right fix.
2. Measure the correct amount. A common starting point is about 1 tablespoon of baking soda per 100 gallons of water. That said, your hot tub size and current readings matter, so it’s better to start small than overdo it.
3. Turn on the circulation. Make sure the jets or circulation system are running so the baking soda can dissolve and distribute evenly.
4. Add it slowly. Sprinkle the baking soda across the surface of the water rather than pouring it all into one spot.
5. Let it circulate. Give the water time to mix thoroughly before testing again.
6. Retest the water. After the baking soda has circulated, check your alkalinity and pH again to see where things stand.
7. Repeat only if needed. If the alkalinity is still low, add a little more in small amounts and test again.

Number four cannot be stressed enough: add it slowly. If you don’t, you will likely find yourself chasing new water balance problems instead of solving the first one.

How Long Should You Wait After Adding Baking Soda to a Hot Tub?

In most cases, you should wait at least 30 minutes after adding baking soda to the hot tub before testing the water again. That should give it time to dissolve and circulate.

However, if you added a larger amount or your hot tub has slower circulation, waiting closer to an hour is usually a safer bet. The goal is to make sure the reading you get is accurate, as testing too soon can give you numbers that don’t reflect where the water is actually settling.

You can usually use the hot tub once the baking soda has fully dissolved and the water has had time to circulate, but it still makes sense to confirm that your levels are in range first.

What to Do if Baking Soda Isn’t the Right Fix

Baking soda can help with low alkalinity, but it won’t solve every hot tub water issue. If the water still looks off, smells strange, feels uncomfortable, or your test readings still aren’t where they should be, there may be something else going on.

Instead of guessing at what to do next, it may help to get a second opinion from someone who works with hot tub water every day. At Clark Pools and Spas, we can help you figure out what your hot tub water actually needs so you can stop experimenting and start getting it balanced the right way. Get in touch to book an appointment today.