Muriatic vs Hydrochloric Acid

Muriatic Acid vs Hydrochloric Acid For Pools - What's The Difference?

When you are researching treatments for different pool conditions online, you may come across the terms muriatic acid and hydrochloric acid. These acids are typically used to treat the same pool conditions, so what’s the difference between them?

In this article we talk about the differences between hydrochloric acid and muriatic acid, various uses for these acids in your swimming pool, and also the dangers involved in using them.

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Are Muriatic Acid and Hydrochloric Acid the Same Thing?

The difference between muriatic acid and hydrochloric acid is in name only. Meaning, yes, these acids are both the exact same thing, and the terms can be used interchangeably.

The difference in naming is due to regional variations of the English language. In Australia, it is typically referred to as hydrochloric acid, while in the United States it is mostly referred to as muriatic acid. This linguistic difference can also vary based on setting.

Once you know that these acids are one and the same, you can begin to learn more about how it is used effectively in pools without being bogged down by the terminology.

Uses for Hydrochloric Acid in Swimming Pools

Hydrochloric acid can be used to adjust the pH and total alkalinity of your pool’s water. Because it has an extremely low pH (less than 3.0, depending on the concentration), only a very small amount is needed in your pool to correct a problem with high pH or high total alkalinity.

If you are planning on doing this, check out this hydrochloric acid calculator to work out the right dose of acid for your swimming pool.

Hydrochloric acid is highly corrosive, which also makes it a good cleaning agent. Some pool owners add slightly larger concentrations to their water as a stain removing product, capable of removing metals, scale, algae, and organic stains.

Another popular use for hydrochloric acid that is related to your swimming pool is acid washing. This process typically occurs when the pool has been drained, and involves a trained professional spraying hydrochloric acid on the walls of your pool as an extremely powerful stain remover.

Check out this guide on where to buy muriatic acid in Australia.

Dangers of Hydrochloric Acid

Hydrochloric acid is incredibly corrosive, and can cause permanent damage to the skin and eyes. Inhalation of the fumes can also lead to permanent lung damage or even sudden respiratory failure.

Because of these risks, we recommend passing off the handling of hydrochloric acid to the professionals unless you have prior experience handling corrosive chemicals or have the necessary protective equipment.

Luckily, it is relatively easy to find pool products that fix the same issues as hydrochloric acid that carry much less risk of bodily injury. We recommend using safer alternatives (such as sodium bisulphate) for balancing your pH or removing algae and stains unless your pool is in need of a professional acid wash.

Louis from Pool Advisor


A chemical engineer by trade, Louis is committed to debunking myths in the pool industry by explaining the underlying chemistry and making it accessible to all.