How to Get Rid of Mosquito Larvae in Your Pool

Written by Michael Dean
November 13, 2023

mosquito larvae in a pool

There’s nothing better than stepping into the crystal clear waters of a clean swimming pool. But sometimes, there can be an uninvited guest lurking in the waters — mosquito larvae. These insects are more than a pesky nuisance; they’re also potential carriers of disease. If left unattended, they can quickly develop into an even bigger problem.

If you’re facing this issue, I’m here to help. In this article, we will be discussing the various strategies and methods to get rid of mosquito larvae from your pool, why they appear, how to identify them, and whether it is dangerous.

Main Takeaways

  • You can use either mosquito dunks or methoprene to get rid of mosquito larvae in your pool.
  • Mosquitoes prefer stagnant water and can get into your pool via rainwater, an exposed pool, and wind.
  • To prevent mosquitoes from laying eggs in your pool, use a pool cover, maintain good water circulation and chemistry, check your surroundings, and regularly maintain your pool.
  • Mosquito larvae itself is not dangerous, but adult female mosquitoes can pose a risk to you and your family!

How to Get Rid of Mosquito Larvae in Your Pool

It’s important to get rid of the mosquito larvae in your pool for two reasons: 1) to prevent annoying mosquito infestations and 2) to reduce the risk of dangerous mosquito-borne diseases. Dealing with full-sized mosquitos? Read my article on getting rid of mosquitos from your pool.

Here are my top tips to help you get rid of mosquito larvae in your pool:

Step One: Treat the Water

Before you move on to more targeted solutions, you need to treat the water. This means balancing your water chemistry to ensure your pool water is in tip-top condition. Make sure your pool is in the recommended levels of chlorine, pH, total alkalinity, calcium levels, etc. Mosquito larvae love stagnant, dirty water. 

Step Two: Add Mosquito Larvicides (Option 1)

Once the water is balanced, you need to treat the larvae themselves. Luckily, there are specially designed products to address this issue, such as mosquito larvicides, also known as “mosquito dunks.” These donut-shaped products contain a naturally occurring bacteria called BTI, which happens to be toxic to mosquito larvae but is safe for humans, pets, and wildlife. It’s a pretty effective and affordable solution for mosquito larvae.

Step Two: Add Methoprene Granules (Option 2)

The alternative to mosquito BTI dunks is methoprene. This is a synthetic growth hormone that impedes the growth and development of mosquito larvae. Available as granules, simply dissolve it into the pool, and it will prevent the larvae from developing for up to 4 weeks! Methoprene is a much better solution if your larvae problem is more widespread across your pool.

Step Three: Clean and Skim the Pool

Once the larvae are dead, it’s time to clean the pool to remove the dead organic matter. To do this, use a pool pole and net to skim the water’s surface to catch any free-floating matter. Follow this up by vacuuming the pool to eradicate any debris that might have settled on the bottom.

Step Four: Empty and Clean Pool Accessories

Once the water is clean, empty and clean the pool’s skimmer and pump baskets. You should also clean out your filter. These are all potential breeding sites for mosquitoes as well.

Step Five: Run the Filter

Mosquitoes love standing water, so run your pump and filter. Running it will also help clear the rest of the mosquito larvae that you weren’t able to clear from your pool.

And, tada! By following these steps, your pool should now be clear of mosquito larvae!

How to Identify Mosquito Larvae in Your Pool

Being able to identify mosquito larvae in your pool is the first step towards controlling their population. They have distinct characteristics, making them relatively easy to spot and recognize. But before we dive into their characteristics, it’s important to note that these insects go through four distinct stages: from eggs to larvae, to pupae, and, finally, adult mosquitoes.

Mosquito larvae are typically small, elongated, and worm-like, around ¼ to ½ inch long. They’re brownish in color and translucent, with a segmented body topped with a distinct head and a narrow, tapered tail at the bottom.

Mosquito larvae can be spotted in still or slow-moving water. Notably, they display a wriggling motion, moving in a distinctive ‘S’ shape, giving them their nickname “wrigglers.” They’ll hang upside down from the surface of your pool.

You can distinguish larvae from pupae in a couple of different ways. Although they look similar, pupae have more curved bodies and will tumble rather than wiggle when swimming away.

How Mosquito Larvae Get Into Your Pool

But how do these pesky insects get into your pool in the first place? However they get into your pool, the main thing to remember is that mosquitoes love stagnant water! 


After rain, water can collect in and around your pool, creating the ideal breeding space for mosquitoes. Mosquitoes typically require stagnant water to lay their eggs. These eggs develop on the water’s surface, and if rainwater on your pool cover or the pool deck accumulates, it’s a surefire breeding ground for the insects.

Exposed Pool

Is your pool uncovered and unprotected? If yes, it may be more susceptible to mosquito infestations. Female mosquitoes can easily access the pool to lay their eggs on the water’s surface. However, on the flip side, even if you cover the pool, any water from rain that might accumulate on top of the cover may be a potential larva site as well! Yikes!


Female mosquitoes might lay their eggs on nearby water bodies, and wind could carry the eggs into the swimming pool. This might include water sources like puddles, bird baths, flower pots, clogged gutters, buckets, containers, and nearby ponds.

How to Prevent Mosquito Larvae in Your Pool

Now that you have managed to clear your pool of mosquito larvae, the next step is to prevent this from happening again. With the proper knowledge on hand, you should be able to swim in your pool whenever you want, larvae-free!

Use a Pool Cover

When the pool is not in use, make sure you cover it with a well-fitted pool cover to keep mosquitoes from laying their eggs in the pool. Don’t have a pool cover already? No worries! Here are some of my top pool cover recommendations.

Maintain Good Water Circulation

As mentioned, mosquitoes thrive in stagnant water. So run your pool’s circulation and filtration system to discourage the insects from settling down and calling your pool home.

Maintain Proper Pool Chemistry

As with almost anything else when it comes to pool maintenance, keep the pool properly balanced with the correct levels of chemicals. Specifically, pay attention to your chlorine levels, which should be between 1 and 3 ppm for effective sanitation. While the chlorine won’t necessarily kill the larvae that may end up in your pool, it does a pretty good job of keeping them out and keeping them from growing.

Check for Standing Water

Keep an eye out for any other sources of still water around your property—these are potential breeding grounds for mosquitoes. Make sure your pool area has good drainage points to prevent rainwater from accumulating.

Regular Maintenance

Regular maintenance is key to maintaining a crystal-clear pool. Follow an effective pool maintenance routine to ensure your pool remains clean and free from mosquito larvae. This includes skimming with a pool net and vacuuming.

All in all, it’s important to regularly inspect the water and ensure it’s up to your standards. Don’t just check the water chemistry. Additionally, check for any debris that might be collecting on the surface and, of course, check for any wriggly creatures in the water.

By following these preventive measures, you should be able to cut down on the likelihood of mosquito larvae infesting your pool.

Is Mosquito Larvae Dangerous?

Technically speaking, no, mosquito larvae are not dangerous to humans. In fact, in their larval stage, they cannot even bite or transmit diseases. At this point, their primary focus is feeding, growing, and preparing for their transformation into adult mosquitoes, which is when the real trouble begins!

Adult female mosquitoes are a much bigger danger to humans. These mosquitoes bite and are responsible for feeding on blood and transmitting diseases. Life-threatening diseases they can carry include malaria, dengue fever, yellow fever, chikungunya, and the West Nile virus. Plus, not to mention, those bites you get from mosquitoes can be incredibly annoying!

Now, back to larvae: While larvae are not dangerous to humans, they are, quite frankly, disgusting and unsightly to look at. And if you swim in a pool containing larvae, you might accidentally swallow some, which is the last thing you’ll want when you’re trying to relax and enjoy your pool!

Get My Free Pool Care Checklist

Download my free, printable pool maintenance checklist to help you accomplish regular pool care tasks for any type of swimming pool.

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Frequently Asked Questions

Will chlorine kill mosquito larvae in a pool?

Chlorine can kill mosquito larvae, but it would have to be in much higher concentrations than normal. But chlorine can be helpful in terms of maintaining the health of your pool and hindering any larvae growth.

What do mosquito larvae eat?

Mosquito larvae primarily feed on microorganisms and organic matter present in the water where they develop. Their diet consists of various tiny aquatic organisms, algae, bacteria, protozoa, and detritus, which is decaying organic matter like dead insects, leaves, and other microscopic particles.fs

Can mosquito larvae survive outside of water?

No, larvae cannot survive outside of water. Mosquito larvae are aquatic organisms and heavily depend on this water for their survival.

Death to Icky Mosquito Larvae!

I hope this article has given you a clear idea of what to do when mosquito larvae infest your otherwise pristine swimming pool. Dealing with larvae is not as difficult as it looks and is as easy as cleaning your pool and putting a mosquito dunk in the water! And once you’re free of larvae, my tips above should help you prevent this issue from recurring.

If you’re still faced with any problems, reach out to me; I’ll be happy to help out!

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