Reasons Why There are Dead Gnats in Pool (Plus 11 Ways to Keep Them Out!)

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Jumping into a pool on a hot summer day is a refreshing experience like none other.  But the experience can become tainted if you notice tiny black specks floating around you in the water.

At first the specks may appear to be dirt floating on the surface, but after closer inspection they may become more apparent as dead gnats.

Swimming with dead gnats in the pool is not an experience that most people want to endure.  While dead gnats are easy to remove from the pool, they can eventually cause issues if enough of them are left floating.

In this post we’ll look at why there may be dead gnats in the pool along with a plethora of ways to keep them out to begin with.

Let’s dive in!

What Are Gnats?

Before we look at why gnats might be in the pool, it’s important to understand exactly what a gnat is.

Gnats are tiny flying insects that have over 3,000 different species. Over 1,200 species of gnats exist in the United States alone.

Like other insects, gnats have a head, thorax and abdomen along with antennae.  They have one pair of wings that allows them to fly moderate distances of up to several miles.

While their appearance can vary depending on species, they are generally only 3 to 6 mm in length.  They have mouth parts that allow for sucking –such as nectar, sap, and sometimes even blood.

Many gnats are black, brown or gray, but can sometimes even be yellowish.  

Gnats reproduce through metamorphosis, meaning they go through egg, larval, pupal, and adult stages. Their larvae, often referred to as “maggots,” are usually legless and worm-like.

While gnats may be somewhat active in the spring and fall, the summer months are generally when they thrive.  The warmth and humidity are favorable for their breeding.

What Do Gnats Eat?

The gnats’ diet will vary depending on the species and their stage in life.  Different species may eat nectar, decaying organic matter, or fungus.  

The larvae state of gnats often prefer decaying matter and develop while in water.  Adults gnats mostly feed on nectar and other plant substances.

The female variety of biting gnats, such as black flies and no-see-ums, will feast on blood.  This includes both animals and humans.

Some species of gnats are also attracted to wet environments.  Such gnats may be found near damp soil or bodies of water.  While many gnats prefer natural water sources, they can still be found near pools.  

Why There Are Dead Gnats in Pool

Finding dead gnats in the pool can seem trivial at first.  Gnats are flying insects, so why do they end up dead in the pool?

For starters, many species of gnats are naturally attracted to bodies of water.  The reflection of light bouncing off the water can further attract these tiny insects.

While it may be possible for gnats to fly away from the pool, there are several reasons why they may end up dead in the water.  

Surface Tension

Once a gnat lands on the water’s surface, it may be impossible to escape due to surface tension of the water.  The surface tension may be too strong for their delicate wings to break away from the water’s hold.


Different species of gnats can fly varying distances that range from several hundred feet to a couple of miles.  Anytime insects fly, they are expending energy.

Flying for extended periods can lead to exhaustion, especially if they are unable to find a decent resting spot.  Exhaust gnats floating on the pool may not have enough energy to return to flight before they meet their demise.


Gnats do not have the ability to swim.  They generally will float in the pool for a while, but eventually can suffocate after a prolonged period of time.

Water Chemistry

Pools are often treated with chemicals, such as chlorine, to keep the water clean and free of algae or other unwanted growth.  These chemicals can be harmful to gnats and other insects that come into contact with the pool.  

How to Get Rid of Dead Gnats in the Pool

Gnats often fly in swarms that can vary from a few dozen to a few thousand.  Due to the light density of gnats’ exoskeletons, dead gnats generally will remain floating on the pool’s surface rather than sinking.

While a few dead gnats in the pool may not be noticeable, thousands of them can be unsightly.   

Aside from dead gnats being visually detracting, they can also provide a source of nutrients for algae and bacteria as they decompose.  

Particularly if there’s a large quantity of dead gnats in the pool, it’s important to remove them from the water to minimize the impact on the water chemistry.

Removing dead gnats from the pool can be accomplished with a few simple steps:

1 – Use a skimmer net to remove dead gnats from the surface.

2 – If your pool has a skimmer basket, check and empty it.  A large load of dead gnats can reduce the skimmer’s effectiveness.

3 – Use a pool brush to gently scrub the pool walls at the waterline to dislodge any dead gnats that may be clinging to the surfaces.

4 – Ensure the filter pressure hasn’t risen too high, which could indicate the filter has become clogged with gnats that have made it past the skimmer basket. 

5 – Check the water chemistry and balance as needed, particularly if the dead gnats have been decomposing in the water for a long while.  

How to Get Rid of Gnats Around Pool

Getting rid of gnats around the pool is the best way to prevent dead ones in the water altogether.  Here’s how to get rid of gnats around the pool:

1 – Proper Water Chemistry

Keeping the pool water properly balanced with correct pH, chlorine and alkalinity can help keep gnats away.  

For instance, fungus gnats are often attracted to acidic environments with a pH of 5.0 to 7.0.  Keeping the pool water balanced to around 7.2 to 7.4 will be less attracting to these types of gnats.

2 – Keep the Pool Clean

Many types of gnats –including their larvae– feed on organic matter, such as leaves and other debris.  Keeping the pool clean can help keep gnats away from the pool. 

Regular skimming and vacuuming will help keep potential food sources for gnats out of the pool.  

3 – Remove Nearby Standing Water

Stagnant water can be breeding grounds for gnats.  Look around the pool area and remove standing water such as birdbaths, buckets, or other containers.

If you have a pond nearby, look into adding circulation such as a pump to help prevent gnats from laying eggs.  

In some instances, leaky pool equipment can be a culprit of standing water.  Repair any drips to help eliminate moisture that gnats might be attracted to.

4 – Use a Pool Cover

A pool cover is a great deterrent of gnats in the pool.  The cover creates a physical barrier preventing them from entering the water.

A pool cover will also help reduce the water’s exposure to sunlight.  Sunlight on the water can provide favorable conditions for gnats to lay eggs.

5 – Natural Repellents

Using natural repellents can help keep gnats away from the pool area. Repellents may include citronella candles, or essential oils or certain plants.

Landscaping with plants such as lavender, rosemary, or peppermint are great ways to help keep gnats, mosquitoes and other insects away.

6 – Use Fans

Gnats are weak fliers, in which wind around the pool can help keep them away.  Strategically placing fans near the pool can prevent gnats, while also adding a comfortable breeze for guests.

Different types of fans are available, such as ceiling, box, tower and high velocity fans.  It’s important that any installed fans are rated for outdoor use for safety purposes. 

7 – Maintain Landscaping

Keeping vegetation trimmed and maintained can help minimize potential food sources and breeding sites for gnats.

Removal of decaying leaves and other debris around the pool will help eliminate food sources for many types of larvae, including that of biting gnats.

8 – Chemical Treatments

While natural options are often preferred, sometimes chemical treatments may be necessary.  

Consider using insecticides specifically labeled for use around pools. Such insecticides may use Pyrethin, which is derived from chrysanthemum flowers, and is generally safe around pools.  

Bti (Bacillus thuringiensis israelensis) is another common insecticide that is generally effective for the larvae of gnats and mosquitoes.  It’s also considered safe around humans, pets and other insects.  

Whatever treatment is chosen, be sure to follow the instructions and safety precautions provided by the manufacturer.

9 – Lighting

Gnats and other insects are often attracted to UV lighting.  

If you have lighting around the pool area, consider changing to yellow or LED lights.  These emit less UV and will be less attractive to gnats.

Conversely, using a bug zapper near the pool will use UV lighting to attract gnats for electrocution. 

10 – Gnat Traps

Gnat or insect traps can be purchased and placed around the pool.  Many of these traps include an attractant along with a sticky surface to prevent the gnats from escaping.

While store-bought traps are effective, there’s also opportunity to use normal household supplies to create your own traps.

DIY Vinegar Trap

The smell of vinegar is similar to that of fermenting fruit, which attracts gnats and other insects.  This makes vinegar the perfect bait in a DIY gnat trap.

1 – Take a small container and fill it about halfway with apple cider vinegar or white vinegar.  A plastic bottle with holes punctured through the cap can be used. 

2 – Add a few drops of dish soap to the vinegar and mix it around. The soap will make it difficult for gnats to escape once they land in the mixture.

3 – Place the containers in several locations around the pool.  

The gnats will be attracted to the vinegar and fly into the trap. Once they land in the vinegar, they will become trapped and eventually drown.

11 – Adjust Swim Time

Gnats are typically most active at dawn and dusk.  If other treatments haven’t been successful in getting rid of gnats around the pool, it may be worth altering your swim schedule to avoid these peak periods.  

Final Takeaway

Since gnats have the ability to fly, it may be surprising to find dead gnats in the pool.  However, their delicate wings are often unable to overcome the water’s surface tension making it impossible to escape.

A few dead gnats in the pool may just be a minor annoyance that requires some quick cleaning.  However, the issue can snowball if large quantities of dead gnats are left floating in the pool.

Dead gnats can decompose in the water, which can disrupt the ever-so-important pool chemistry.  There’s also a risk that they could clog the filtration system if not removed.  

Fortunately, similar to termites and other insects, there are targeted treatments along with preventative measures that can be taken to help get rid of gnats around the pool.  A combination of the measures can be taken to further improve the odds of success.

Happy (Pest-Free) Swimming!

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