Austin's Algae: Is Cheap Shock Fueling Pores?

By Franklin Everett Shaw

December 22, 2025

The air in Austin hangs heavy with humidity, especially in the summer. It’s the kind of humidity that clings to you, making even a short walk feel like a marathon. But for many Austinites, relief comes in the form of a backyard pool, a community pool, or even a dip in Barton Springs. However, that refreshing escape can sometimes come with an unwelcome side effect: itchy, irritated skin.

The culprit? Often, it’s algae. And in Austin, with its warm climate and abundant sunshine, algae blooms in pools are a persistent problem. But it’s not just the presence of algae itself; it’s the whole chain of events that follows, often exacerbated by well-intentioned but misguided pool maintenance practices. Let’s dive into how to protect your skin and enjoy your Austin summer without the itch.

First, let’s talk about the algae itself. Algae isn’t inherently dangerous. It’s a plant, after all. But certain types of algae, particularly blue-green algae (cyanobacteria), can produce toxins called cyanotoxins. These toxins can cause skin irritation, rashes, and even more severe health problems if ingested. Even non-toxic algae can disrupt the pool’s chemical balance, leading to increased chlorine demand and the formation of irritating byproducts.

Now, here’s where the Austin-specific part comes in. The geology of Central Texas, with its limestone bedrock, contributes to hard water. Hard water makes it more difficult to maintain proper pool chemistry. This creates a more favorable environment for algae growth. Furthermore, the intense Texas sun accelerates algae growth, making it a constant battle for pool owners.

So, what can you do? The first line of defense is proper pool chemistry. This isn’t just about dumping chlorine in the pool. It’s about maintaining a balanced pH, alkalinity, and calcium hardness. Invest in a reliable test kit and test your pool water regularly, at least twice a week. Don’t rely solely on test strips; liquid test kits are more accurate.

Here’s a concrete example: Let’s say you live in the Zilker neighborhood and your pool is constantly battling algae. You’re adding chlorine, but the algae keeps coming back. The problem might not be the amount of chlorine, but the pH. If your pH is too high (above 7.8), the chlorine becomes less effective. Lowering the pH to the ideal range of 7.2-7.6 will significantly improve chlorine’s ability to kill algae.

Another critical factor is the type of pool shock you use. Many pool owners opt for cheaper calcium hypochlorite shock. While effective in the short term, it can raise calcium hardness levels, further contributing to hard water issues and making algae control more difficult in the long run. Consider using non-chlorine shock (potassium monopersulfate) periodically to oxidize organic contaminants without affecting calcium levels. This is especially important in areas like Westlake, where the water is already naturally hard.

But what if you’re already dealing with an algae bloom? Don’t just throw more chlorine at it. That can actually make the problem worse by creating irritating chloramine byproducts. Instead, follow these steps:

Test and balance your water: Ensure your pH, alkalinity, and calcium hardness are within the ideal ranges.
Brush the pool walls and floor: This dislodges the algae, making it easier for the chlorine to kill.
Vacuum the pool: Remove the dead algae and debris.
Shock the pool: Use a high-quality shock, following the manufacturer’s instructions carefully.
Run the filter continuously: This helps circulate the water and remove dead algae.
Clean the filter: A clogged filter reduces its effectiveness.

Now, let’s talk about protecting your skin. Even with perfectly balanced pool chemistry, some people are more sensitive to chlorine and other pool chemicals. If you’re prone to skin irritation, take these precautions:

Shower before and after swimming: This helps remove sweat, dirt, and other contaminants that can react with chlorine.
Apply a barrier cream: A thick moisturizer or a specialized swim cream can help protect your skin from chlorine and algae. Look for products containing ingredients like petrolatum, dimethicone, or shea butter.
Wear a rash guard: This provides a physical barrier between your skin and the pool water.
Rinse off immediately after swimming: Don’t let the pool water dry on your skin.
Moisturize your skin: Chlorine can dry out your skin, so apply a moisturizer after showering.

But what if you’ve already developed a rash? The first step is to stop swimming immediately. Wash the affected area with mild soap and water. Apply a cool compress to soothe the irritation. Over-the-counter hydrocortisone cream can help reduce inflammation and itching.

However, if the rash is severe, persistent, or accompanied by other symptoms like fever or difficulty breathing, see a dermatologist. It’s crucial to find a dermatologist in Austin who is familiar with environmental irritants common in Texas, such as algae toxins and reactions to pool chemicals. They can properly diagnose the cause of your rash and recommend the appropriate treatment.

A common mistake many Austinites make is neglecting their pool filter. A dirty or malfunctioning filter can significantly reduce the effectiveness of your pool chemicals and contribute to algae blooms. Clean your filter regularly, following the manufacturer’s instructions. Backwash your sand filter or clean your cartridge filter as needed. Consider replacing your filter media every few years to ensure optimal performance.

Another pitfall is relying too heavily on automatic pool cleaners. While these devices can help keep your pool clean, they don’t replace the need for regular brushing and vacuuming. Algae can cling to the pool walls and floor, even in areas that the automatic cleaner can’t reach.

Finally, remember that pool maintenance is an ongoing process. Don’t wait until you have an algae bloom to start taking care of your pool. Regular testing, balancing, and cleaning are essential for preventing problems and keeping your pool water clean and safe. By taking these steps, you can enjoy your Austin pool without the worry of skin irritation. And that’s a win for everyone.