Cicadas (and other small dead animals) in Swimming Pools

Imagine stepping outside to check your pool only to be greeted by a deafening roar that drowns out even your car radio. That's exactly what happened to Eric Knight, host of the Rule Your Pool podcast, when millions of cicadas emerged in his Charlotte, North Carolina neighborhood after 13 years underground. What started as a natural phenomenon quickly became a pool maintenance challenge that offers valuable lessons for all pool owners dealing with organic debris.

The Great Cicada Emergence: A Once-in-a-Generation Event

Cicadas are truly one of nature's most remarkable insects, following precise cycles that have fascinated scientists for decades. These large insects, measuring up to two inches long with distinctive red or green eyes, spend either 13 or 17 years developing underground before emerging in massive numbers.

Cicadas come out of the ground every 17 or 13 years depending on the brood over a million per acre in the areas that they have been in for a long time.

— Eric Knight, Rule Your Pool Podcast

The sheer volume is staggering. Knight explains that cicadas have evolved a unique survival strategy: overwhelming predators through sheer numbers rather than speed or intelligence. This evolutionary approach means that when they emerge, they literally carpet entire neighborhoods, creating both an ecological feast for predators and a maintenance nightmare for pool owners.

Different regions experience different cicada broods on varying cycles. Knight discovered this firsthand when he moved from Northern Virginia (which had Brood X emerging in 2021) to Charlotte, North Carolina (which has Brood XIX on a 13-year cycle, emerging in 2024). Understanding your local brood cycle can help you prepare for these periodic invasions.

The Hidden Impact on Pool Chemistry

What makes this episode particularly valuable is Knight's real-time observation of how organic debris affects pool chemistry. Despite maintaining his regular chemical routine, he noticed a significant change in his pool's chlorine demand coinciding with the cicada emergence.

I am not able to hold chlorine very well. It's pretty astounding because nothing else has really changed.

— Eric Knight, Rule Your Pool Podcast

The science behind this chlorine demand becomes clear when you understand what cicadas bring to your pool water. First, they're covered in tree sap from digging into branches to lay their eggs. Second, and perhaps more importantly, scientific research reveals that decomposing cicadas are extremely high in nitrogen, phosphorus, and carbon – particularly nitrogen.

Knight references a study from the Journal of the North American Benthological Society titled "The Deposition and Decomposition of Periodical Cicadas in Woodland Aquatic Ecosystems," which confirms that these insects significantly alter water chemistry as they decompose. The nitrogen influx explains the combined chlorine issues he experienced, even without typical nitrogen sources like swimmer waste.

Practical Pool Management During Cicada Season

The good news for pool owners is that cicadas are relatively manageable compared to other organic debris. They float at the water's surface, making them easy to spot and remove with a standard pool net. Knight found most cicadas collected in his skimmer basket, which made regular removal straightforward.

I have pulled out over 200 in the last day. I'm netting them out so rapidly and they keep getting into the pool.

— Eric Knight, Rule Your Pool Podcast

The key is staying vigilant during the 2-6 week emergence period. Daily skimming becomes essential, and you may need to empty skimmer baskets more frequently than usual. Knight emphasizes that physical removal is always the first and most important step in maintaining water quality.

For chemical management during cicada season, pool owners should expect increased chlorine demand and be prepared to adjust their sanitization schedule accordingly. Knight typically chlorinated twice weekly but found he needed to monitor levels more closely during the emergence.

Beyond Cicadas: Managing Other Small Animals in Your Pool

Cicadas aren't the only small animals that unfortunately end up in swimming pools. Knight also discusses finding mice, frogs, and other small creatures in his pool – a reality most pool owners face at some point.

The other day I found two dead mice in my pool. They were floating too. I was able to net them out. What does that do for my chemistry?

— Eric Knight, Rule Your Pool Podcast

While the contamination from small animals varies depending on size and decomposition time, the principle remains the same: remove them as quickly as possible. Small animals like mice and frogs bring organic matter and potential pathogens into your pool, though typically in much smaller quantities than a cicada invasion.

The impact on chemistry from occasional small animals is generally minimal if removed promptly, but Knight notes they certainly don't help with chlorine demand. The sooner you can net them out, the less impact they'll have on your water balance and sanitizer levels.

The Bigger Picture: Understanding Organic Load

This cicada experience illustrates a crucial concept in pool maintenance: organic load and its impact on sanitizer demand. Whether it's cicadas, leaves, pollen, or swimmer waste, organic matter in your pool consumes chlorine as it breaks down.

Knight's pool remained crystal clear throughout the cicada invasion, thanks partly to his use of enzymes (CV600) and regular maintenance routines. This demonstrates that while organic debris increases chemical demand, proper maintenance practices can handle even unusual situations like mass insect invasions.

Understanding this relationship helps pool owners make informed decisions about chemical adjustments when facing high organic loads from any source. Rather than simply adding more chemicals, the most effective approach combines physical removal, enzyme treatment, and appropriate sanitizer adjustments.

Preparing for Nature's Challenges

The cicada emergence serves as a reminder that pool maintenance isn't just about routine chemical balance – it's about adapting to changing conditions. Whether you're dealing with periodic cicada emergencies, seasonal pollen loads, or storm debris, the principles remain consistent.

There is no replacement for getting rid of solids, basically. Physically removing things is always going to be a good idea.

— Eric Knight, Rule Your Pool Podcast

For pool owners in areas with predictable cicada cycles, knowing your local brood schedule allows you to prepare. Stock up on replacement skimmer baskets, ensure your pool net is in good condition, and consider adjusting your chemical monitoring routine during emergence periods.

The ecological benefits of cicada emergences – providing food for predators and allowing other prey species to thrive – remind us that these natural events serve important purposes beyond creating pool maintenance challenges. Understanding and working with these natural cycles, rather than fighting them, leads to better outcomes for both pool owners and the environment.

Knight's real-time documentation of this phenomenon provides valuable insights that go far beyond cicadas. His experience demonstrates how careful observation, scientific curiosity, and practical problem-solving combine to create better pool maintenance practices. Whether you're dealing with cicadas, other insects, or any organic debris, the lessons remain the same: remove physical contaminants quickly, understand their chemical impacts, and adjust your maintenance routine accordingly.

Episode Chapters

• 00:00 Introduction - The Cicada Invasion
• 02:30 Understanding Cicada Cycles and Broods
• 05:45 Impact on Pool Chemistry
• 08:20 Practical Removal Strategies
• 11:10 Other Dead Animals in Pools
• 13:15 Final Thoughts and Takeaways