Austin’s Algae: Is Pool Sunscreen Toxic Now?

By Franklin Everett Shaw

April 8, 2026

The Barton Springs Pool is a jewel of Austin, a place where generations have cooled off during scorching Texas summers. But lately, something’s been amiss. An increase in algae blooms has sparked concerns, and fingers are pointing at a surprising culprit: sunscreen. Specifically, the chemicals in many popular sunscreens are suspected of contributing to the problem. It’s time we, as Austinites, take a hard look at what we’re slathering on our skin before diving in.

The issue isn’t just about aesthetics; it’s about the health of our beloved swimming holes. Certain sunscreen ingredients, like oxybenzone and octinoxate, are known to disrupt aquatic ecosystems. These chemicals can act as endocrine disruptors in fish and other wildlife, and they’ve been linked to coral reef damage. While Austin isn’t exactly known for its coral reefs, the principle remains the same: these chemicals can negatively impact the delicate balance of our freshwater ecosystems, contributing to algae blooms.

So, how do you know if your sunscreen is a potential problem? Start by reading the label. Look for these ingredients to avoid:

• Oxybenzone: A common UV filter that’s been shown to cause coral bleaching and disrupt hormone function in aquatic life.
• Octinoxate: Another UV filter with similar negative impacts on aquatic ecosystems.
• Homosalate: While less studied than oxybenzone and octinoxate, some research suggests it can also disrupt hormone function in aquatic life.
• Octocrylene: Can accumulate in aquatic organisms and potentially cause harm.
• Avobenzone: While generally considered safer than oxybenzone, it can break down into harmful byproducts in the presence of chlorine.

It’s not enough to just avoid these chemicals; you need alternatives that actually protect your skin. Luckily, Austin is a health-conscious city, and there are plenty of eco-friendly, algae-safe sunscreens readily available.

Here’s what to look for:

• Mineral Sunscreens: These sunscreens use zinc oxide and/or titanium dioxide as the active ingredients. These minerals are physical blockers, meaning they sit on top of the skin and reflect UV rays, rather than being absorbed into the skin like chemical sunscreens. They are generally considered safer for aquatic environments.
• “Reef-Safe” or “Reef-Friendly” Labels: While there’s no official regulation of these terms, they generally indicate that the sunscreen is free of oxybenzone and octinoxate. However, it’s still important to check the ingredient list to be sure.

Where can you find these sunscreens in Austin?

• Whole Foods Market: Whole Foods carries a wide selection of mineral sunscreens, including brands like Badger Balm, Thinkbaby, and Babo Botanicals. Look for the “reef-safe” labels and check the ingredient lists. The Whole Foods on North Lamar is a good starting point.
• People’s RX: This local Austin pharmacy chain is known for its commitment to natural and sustainable products. They carry a variety of mineral sunscreens, including some that are specifically formulated for sensitive skin. Check out their location on South Lamar.
• Wheatsville Co-op: Another Austin institution, Wheatsville offers a curated selection of natural and organic products, including mineral sunscreens. Their Guadalupe Street location is a convenient option.
• Online Retailers: If you can’t find what you’re looking for locally, online retailers like Amazon and Thrive Market offer a wide selection of mineral sunscreens. Just be sure to read reviews and check the ingredient lists carefully.

Beyond choosing the right sunscreen, proper pool maintenance is crucial for minimizing algae growth. Austin’s hot climate and intense sunlight create ideal conditions for algae to thrive. Here are some tips specific to Austin’s environment:

• Regularly Test and Balance Your Pool Water: Austin’s tap water can be hard, which can affect the pH and alkalinity of your pool water. Test your water regularly and adjust the chemicals as needed to maintain a proper balance. Leslie’s Pool Supplies on Research Boulevard can help with testing and advice.
• Maintain Proper Chlorine Levels: Chlorine is essential for killing algae and bacteria. Aim for a chlorine level of 1-3 ppm. Consider using a salt water chlorinator, which can be a more consistent and environmentally friendly option than traditional chlorine tablets.
• Brush and Vacuum Your Pool Regularly: This helps to remove algae and debris that can contribute to algae growth. Pay particular attention to areas that are shaded or have poor circulation.
• Clean Your Filter Regularly: A dirty filter can reduce the effectiveness of your pool’s circulation system, creating ideal conditions for algae to grow. Backwash your filter regularly and clean it thoroughly at least twice a year.
• Consider a Phosphate Remover: Phosphates are a food source for algae. Using a phosphate remover can help to starve algae and prevent blooms.
• Use a Pool Cover: When your pool is not in use, cover it to reduce sunlight exposure and evaporation. This can help to prevent algae growth and save water.

One common mistake developers make when dealing with pool maintenance is neglecting the importance of proper circulation. Stagnant water is a breeding ground for algae. Ensure your pool’s pump is running for at least 8 hours a day, and consider adding a fountain or other water feature to improve circulation.

Another pitfall is over-reliance on algaecides. While algaecides can be effective in killing algae, they are often a temporary solution and can be harmful to the environment. Focus on addressing the underlying causes of algae growth, such as poor water balance, inadequate circulation, and high phosphate levels.

Finally, don’t underestimate the power of education. Talk to your neighbors, friends, and family about the importance of using eco-friendly sunscreens and proper pool maintenance techniques. The more people who are aware of the issue, the more likely we are to protect our beloved swimming holes.

Let’s keep Barton Springs, Deep Eddy, and all of Austin’s swimming spots clean and healthy for generations to come. By making informed choices about our sunscreen and pool maintenance practices, we can all do our part to protect these precious resources. It’s not just about swimming; it’s about stewardship.