Use Borax in Your Pool to Raise pH for Less Money

If your pool’s pH is low and your total alkalinity (TA) is in range, use Borax (sodium tetraborate). However, if your pH and TA are low, use soda ash (sodium carbonate).

These are slightly cheaper alternatives to pool pH Increaser or pH Up. And they can usually be found in the laundry aisle of your local grocery store. Soda ash is often sold under the name Washing Soda.

Using borax adds a small amount of borates to your water. However, a normal dose to increase the pH doesn’t add enough to make a real difference.

How to Add Borax to Raise pH

1. Test your pH and total alkalinity, and make sure total alkalinity is in range.
2. Figure out how much borax you need with a pool chemical calculator. The amount depends on your pool size, your current pH, and your alkalinity.
3. Add about half the calculated amount first. It’s easier to add more than to bring pH back down.
4. Dissolve the borax in a bucket of warm pool water. It dissolves slowly in cold water.
5. With the pump running, pour it slowly in front of a return jet.
6. Let it circulate for at least a few hours, then retest and adjust if needed.

Use plain borax with no added fragrance or detergent.

What is Borax?

Borax is sodium tetraborate. It’s a natural mineral first mined in Death Valley back in the 1800s. Borax has a pH of about 9.2 to 9.5. So when you add it to your pool, it has a gentler effect on raising pH compared to using soda ash or pH Increaser, which is sodium carbonate (pH of about 11.4).

Borax is mainly used as a laundry booster. You add it with detergent to help remove stains, soften the water, and make your whites brighter. Personally, I’ve never used it in the washing machine, so I don’t really know.

It’s also used as a cleaner, similar to baking soda.

A baking soda (sodium bicarbonate) solution has a pH of about 8.3. Since 8.3 is only a little above normal pool pH (7.4 to 7.6), it raises total alkalinity a lot while barely moving pH. And it can never push pool water much above about 8.3 on its own.

My Take on Using Borax as an Algae Inhibitor? 

I keep seeing all types of comments saying that Borax and baking soda are all that is necessary to maintain crystal-clear water, with no algae for the entire pool season.  Kind of difficult to believe, but so many people swear by it.

Staying on top of algae growth is a chore, especially if you live in a hot climate.  Even employees at the pool store will say, “You’re gonna have algae no matter what you do”.

“You’re gonna have algae no matter what you do” is BS! It absolutely matters WHAT YOU DO!

Adding Borax to your pool raises pH. That’s it.

Yes, getting your pH in range (7.4 to 7.6) does help your chlorine to work better, which will prevent algae. But borax alone does not keep algae away.

The best defense against pool algae is chlorine. Period. Keep your pH/alkalinity balanced and your chlorine in range, and you’d be just fine.

Is Borax The Same as Adding Borates

Borax raises your pH, and it adds a small amount of borates. But not enough to add a significant amount of borates if you’re just using it to keep your pH in check.

Adding a significant amount of borates (30 to 50 ppm) helps to buffer pH, which is another way of saying it helps keep your pH in range. This is great if you have a saltwater pool. Saltwater generators (SWG) are prone to scaling due to high pH spikes happening inside the salt cell.

And some people say it makes the water feel good on your skin. I personally didn’t notice a difference, but you can be the judge if you want to try it.

However, adding borates is optional. And I don’t recommend it. This is just an added chemical expense for very little payoff.

Frequently Asked Questions

Is pool store pH Increaser the same as borax?

Most pool store pH Increaser is soda ash, not borax. Check the label. Some brands sell borax-based pH products, usually labeled as sodium tetraborate.

Can I use laundry borax in my pool?

Yes, as long as it’s plain borax with nothing added.

Will one dose of borax buffer my pH?

Not really. A pH dose adds some borates, but far less than the 30 to 50 ppm needed to make a noticeable difference.

Do I need borates at all?

No. They’re a nice extra, not a requirement. Keeping total alkalinity in range does most of the work of steadying pH.

Key Takeaways

• If my pH is low but my total alkalinity is in range, I use borax (sodium tetraborate). If both my pH and alkalinity are low, I switch to soda ash instead.
• Borax and soda ash are just cheaper versions of pool pH Increaser. I can usually grab them in the laundry aisle, where soda ash is often sold as Washing Soda.
• I always use plain borax with no added fragrance or detergent. Anything extra does not belong in my pool water.
• Borax is gentle. Its pH sits around 9.2 to 9.5, so it nudges my pool pH up without the big jump I’d get from soda ash, which has a pH closer to 11.4.
• I add about half the calculated dose first, dissolve it in a bucket of warm pool water, then pour it slowly in front of a return jet with the pump running. It’s much easier to add more than to bring pH back down.
• Borax raises pH, and that’s it. It does not keep algae away, so I still rely on chlorine as my real defense and treat borates as an optional extra I can skip.