How to Keep Mosquitoes Out of Water Fountains Safely

Water fountains are fantastic centerpieces on your yard. However, it’s also the perfect breeding place for mosquitoes. If your water fountain is kept stagnant for days, mosquitoes will lay eggs on it and convert it into a massive breeding ground. Soon enough, your property is mired with the insect pests. With this, knowing how to keep mosquitoes out of water fountains is the key.

Summit Mosquito
BTI Dunks
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Bactimos Mosquito
Control Dunks
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Altosid Pro-G
Mosquito Larvicide
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clarke Natural DT
Mosquito Larvicide
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Removing the water fountain isn’t the solution. You can still enjoy the soothing sound of falling water but with some useful hacks.

How to keep mosquitoes out of water fountains

Mosquitoes are everywhere, which makes it tricky to shield your fountain from their egg-laying pursuits. Still, you can use the following tips. Below, we also reviewed commercial solutions that will provide instant results and minimal monitoring.

-Run the fountain regularly

The easiest way to dodge the reproduction of mosquitoes on your fountain is to run it regularly. By disturbing the water, you’re also making it impossible for mosquitoes to lay eggs. If ever there are eggs and larvae on the water, the pumping and gushing motion will likely kill some but not all.

Also, running the fountain prevents it from being the source of stagnant water. Aside from repelling mosquitoes, it will also discourage other critters from using it as a source of moisture.

Nevertheless, you don’t have to run the fountain all day long. Letting it flow for an hour or two daily should be enough to prevent insects from using it as a breeding ground.

 If you’re going on a vacation or leaving the fountain stagnant for days, you can use BTI dunks and other chemical solutions we’ve reviewed below.

-Clean the fountain periodically

Another guaranteed solution on how to keep mosquitoes out of water fountains is to clean it regularly. You can mix the water with a fountain cleaner, let it sit for a while, then drain it. This will remove any algae or larvae on the fountain.

Aside from that, it will also increase the lifespan of the pump since you’re removing any residue and potential blockages.

You can also use a mixture of vinegar. Aside from running it through the pumps, you can also use a vinegar and water spray to wipe the external parts of the fountain. As one of the most effective cleaning agent, vinegar has deodorizing and anti-microbial properties. Since vinegar is food-grade, it’s very safe to use, be it for indoor or outdoor water fountains.

If you noticed that the pump of your outdoor water fountain is noisier than before, you should tap the help of a technician. It might need recalibration or maintenance.

-Grow mosquito-repelling plants near the fountain

If you don’t want to use any chemical on your water fountain, your best bet is growing repellent plants around it. This isn’t 100% guaranteed to work, especially for large fountains. But still, it will decrease the chance of mosquitoes going near the water.

Marigold is the top option here. Aside from its vibrant yellow and orange color, it has a smell that mosquitoes find unappealing. Planting this around the fountains as close as possible is effective in reducing the mosquito population nearby.

Moreover, you can choose plants like lavender, mint, jasmine, and rose geranium. These are all decorative plants that bear a mosquito-repellent property. In fact, you can crush some lavender and geranium leaves to use as an add-on for your stagnant water fountain. If possible, you can apply essential oils on the fountain to keep the insects away.

-Use a larvicide solution

If the mosquitoes in your area are invasive, you need a tougher solution. Using larvicides are effective in killing the larvae and eggs, plus it has a residual effect that protects your water fountain for weeks.

Larvicides can either work as a poison to the mosquitoes or as a growth regulator. When the larvae get in contact with the chemical, it will stymie their growth which will slowly lead to death.

Take note that typical insecticides aren’t the option here. You have to purchase a specific larvicide that doesn’t contain highly toxic chemicals and acidic properties that will damage your fountain.

If possible, look for a larvicide with natural ingredients that are safe to use on big fountains. Also, there are larvicides formulated specifically for stagnant water like fountains and pools. Moreover, these are safer options that will not cause damage to the motor of your fountain.

-Sprinkle cinnamon on the water

Cinnamon isn’t just a delicious spice. It’s also an excellent repellent for mosquitoes, both indoors and outdoors. For your water fountain, you can sprinkle cinnamon powder or let a few cinnamon barks float around. The extracts and oils from these barks will mix with the water and make it unappealing for mosquitoes.

Moreover, adding 5% cinnamon into the water fountain will kill all the mosquito larvae within 24 hours. And if you want a more potent solution, you increase the concentration to 15% to kill all the eggs and larvae within six hours.

Female mosquitoes will also avoid the cinnamon-treated water fountain; thus, preventing the reproduction of more larvae.

Aside from being a potent mosquito killer, cinnamon also gives off a nice scent. That’s why it’s a great alternative to synthetic larvicides.

The only downside to using cinnamon to your fountain is it may leave a brown color on the water. Other than that, there’s no harm in trying this solution.

-Use mosquito-eating fish

If you want a solution that also doubles as added aesthetic, you can place mosquito-eating fishes on your fountain. Some of the good examples are Koi, Shubunkin Goldfish, Sarasa Comets, and more.

The only downside to these fishes is the added maintenance and care that you have to do. So to skip the hassle, you can opt for Guppy fish. These are small and colorful fishes that can survive without an oxygen tank. Also, Guppies can thrive on mossy fountains and harsh environments.

In addition, Guppies can eat larvae equivalent to their body weight per day. This fish is a cost-efficient choice to get rid of larvae when your fountain is stagnant or has a less disturbed area.

If you’re leaving your fountain off for days, you can deploy dozens of Guppies with a few water plant leaves. The leaves will be their initial food source. When the mosquitoes lay eggs on the surface, the fishes will start to do their job.

-Go deep

Mosquito larvae survive on shallow waters that are less than 24 inches deep. If you’re yet to have your fountain installed, opt for one with a water reservoir of about 2 feet. Also, fountains with vertical walls are less likely to be the harborage of mosquitoes since there are no shallow parts. Also, features with sloping steeps make it hard for mosquitoes to lay eggs.

If these features are impossible to achieve or your current fountain doesn’t have one, you can still use the other solutions we discussed here.

-Use essential oils

If you don’t want any harmful chemicals on your water fountain, you can use essential oils instead. However, you may need to use a large amount, especially for massive fountains.

The likes of lavender, citronella, peppermint, eucalyptus, and cinnamon oil are effective in keeping mosquitoes away. However, never put oil on your fountain if you have fishes in it. Also, you should check the effect of essential oils on beneficial insects and animals around.

Overall, essential oils are safe to use, but you should avoid direct skin contact when using minty and citrusy oils. These are acidic and potent and may irritate your cutis.

-Remove the algae

When mosquito larvae hatch, algae become their food source. By curbing the algae population, you’ll also discourage mosquitoes from using your fountain as a breeding place. Pairing this with another repellent method mentioned here should shield your fountain from any insect pest.

Aside from removing algae, you’ll also get to keep your fountain aesthetic and sanitary. You can clean it manually or use a synthetic algaecide for water fountains.

-Keep the vegetation trimmed

If you have non-repellent plants around your water fountain, it’s best to trim it short to avoid mosquitoes from harboring in it. Unkempt vegetation becomes the perfect hangout place for mosquitoes while they wait for the perfect timing to lay their eggs on the fountain.

Remove weeds and dead plants where mosquitoes can hide. If you’re revamping your garden, it’s best to grow plant mosquito-repelling plants as we’ve mentioned here.

-Get rid of other mosquito harborages nearby

Aside from protecting the water on your fountain, you should also target other possible harborages of mosquitoes around your yard. By eliminating the mosquito population, you’re also shielding your fountain from future infestations.

Take note that mosquitoes bring various diseases, regardless if they harbor on your fountain or not.

-Let the frogs hop in

Tadpoles and frogs feed on mosquito larvae. Letting these critters roam your fountain is a big help. However, not everyone wants to have jumpers around. In the end, it’s a matter of personal choice.

-Use BTI dunks

If there’s one guaranteed solution that we highly recommend, it would be using BTI dunks. These doughnut-looking products are packed with BTI or Bacillus thuringiensis israelensis bacterium that will feed on mosquito larvae.

BTI dunks can be used on pools, fountains, and other stagnant water that can’t be drained. It’s safe for humans or pets that will be in contact with the source of water where it’s used.

These dunks last for weeks. For smaller containers with water, you can crush the dunk and sprinkle it.

How BTI dunks work

Each piece of mosquito dunks is about 2 inches in diameter or roughly the size of a cookie. It also has a narrow hole in the middle so you can keep it in place using stakes or sticks.

Since dunks are lightweight, it can float on water. Overall, it has a subtle scent, but you won’t even notice it once you got this soaked in water.

Moreover, mosquito dunks are very potent in killing mosquito larvae while remaining gentle on other living things. In fact, a single dunk soaked in water can kill thousands of larvae in just a few days. This is why dunks are the best mosquito solution for massive fountains and basins.

In addition, mosquito dunks kill 2,500 species of mosquitoes, including the Asian tiger mosquito known for transmitting Zika virus, yellow fever, dengue fever, and other diseases.

How to get the best results from BTI mosquito dunks

If you want to reap the best results from BTI dunks, you should keep the following points in mind:

*Use the right ratio

The rule of thumb is one BTI dunk for every 100 square feet of water. You don’t have to worry about the depth of the water since larvae are released on the surface and stay on the surface.

If you discovered that your water fountain is highly infested with mosquitoes, you could use more than one dunk for the same surface water area. Not unless this is the case, using too many dunks will just be a waste of money.

*Use it everywhere

Once your water fountain is treated with dunks, the mosquitoes will now look for another hatching place. So with the extra BTI dunks at hand, you should use some on your pool (unless it’s already treated with chlorine), septic tanks, pet bowls, feeding troughs, gutters, and other areas where water can get trapped.

Take note that if the dunk can cause clogging, you can crush or chop it into pieces before the application. It works with the same efficiency. However, you should watch out for your pet that might accidentally ingest the dunk pieces.

*Use it all year round

BTI dunks are year-round solutions to mosquitoes. These are handy during the months of February, March, and April where mosquitoes peak in reproduction.

Even if you’re out of the breeding months, you should still be consistent in applying dunks on your fountain. Since it’s safe for regular use, there’s nothing that you should be worried about.

*Replace it regularly

Depending on the dunk you purchased, most will last for up to 30 days. After this, you should replace the dunks to sustain the larvae-killing effect on your fountain.

*Anchor it with a string or stick

If your fountain has a strong pumping motion, you should anchor it so it won’t block the water flow. If you’re using the dunk on a pond or bigger water sources, make sure that it doesn’t get caught in the weeds or drive away by rainwater or strong winds.

Anyway, you don’t have to be conscious about where to put the BTI dunks since most of these products will work just the same even if exposed to direct sunlight.

*Change the water too

There’s no point in dipping new dunks to fountain water that has been in use for months. As part of cleaning your fountain, make sure that you drain the old water and replace it with a fresh supply.

This will remove the dead larvae and give the dunk bacteria a fresh place to prosper.

*Don’t let your pets eat it!

Let me make this clear: your pets will be fine even if they ate the dunk. Some would have mild stomach problems, but it will not poison them.

However, if your dog or your cat eats the dunks, it will not serve its true purpose. If you don’t notice it right away, the mosquitoes will go back to the fountain and lay eggs.

Top BTI Dunk Options

OUR TOP PICK: Summit Mosquito BTI Dunks

Product Name: Summit Mosquito BTI Dunks

Product Description: The Summit Mosquito BTI Dunks are made to last for at least 30 days once submerged in water. It’s effective beyond the mosquitoes’ generation. The active ingredients of the dunk will be released on the surface, which then settles at the bottom for utmost protection against egg-laying mosquitoes. The best thing here is that repetitive drying and soaking will not affect the efficacy of the dunks. Also, it can endure direct sunlight.

Offer price: $$$

Availability: InStock

  • Lasting effect
  • Value for money
  • Safety


Moreover, this is safe to use on feeding troughs and fish habitats. Rest assured that it will not harm any animal.

Once placed on water, the dunks will start killing the larvae within an hour. It’s a potent solution yet a very low-impact product.

Lastly, the Summit Dunks are available in 2, 6, and 12-pack versions. All of which are extremely affordable.


✔️Lasts for more than 30 days

✔️Repetitive drying and wetting won’t ruin its effect

✔️Safe for fish habitats


❌None so far


Bactimos Mosquito Control Dunks

how to keep mosquitoes out of water fountains

If you have a large fountain and you need to treat other water reservoirs, you should consider the Bactimos Mosquito Control Dunks. It comes in a pack of 20 with BTI bacterium of around 10%.

You can use this on fountains, gutters, birdbaths, feeding troughs, rainwater, flower pots, and more areas where water gets trapped.

Just like Summit’s BTI dunks, the bacterium will be released in the surface first to kill the larvae. Placing dunks all over the water containers on your yard will give you peace of mind that no mosquitoes can breed in it.

Aside from mosquitoes, it can also kill fungus gnats which is a big plus for gardeners.

✔️Come in a pack of 20
✔️Kills fungus gnats too
✔️Safe to use around the yard and other bodies of water

Alternative options

Altosid Pro-G Mosquito Larvicide

If you’re looking for a potent solution, an alternative is the Altosid Pro-G Mosquito Larvicide. It has 1.5% of Methoprene that can be applied directly on non-crop areas like water fountains, snow pools, tidal marshes, retention ponds, and more.

It provides 30 days of protection from breeding and biting adult mosquitoes.

The 2.7-pound gallon can treat up to 20,000+ gallons of water. For such a decent price, this is already an affordable solution.  It’s a perfect treatment for standing water as long as you don’t have fishes and other living things in there that you don’t want to exterminate.

Since this is a synthetic larvicide, it’s guaranteed to kill the larvae upon contact. Anyway, you should ask a fountain technician before using this product. This is to avoid damages to the pump should the treatment turn out to be incompatible with the fountain material.

✔️Treats up to 20,000+ gallons
✔️30-day protection
✔️Guaranteed kill
❌Not safe for fishes

clarke Natural DT Mosquito Larvicide Tablet

Another option to consider is the clarke Natural DT Mosquito Larvicide Tablet. Upon application, it will kill the larvae within hours and sustain the effects for up to 60 days.

This tablet uses Spinosad as the active ingredient. It’s safe to use on standing water with fishes as well as in water fountains, feeding troughs, water gardens, and fish ponds.

It has a slow-release formula that keeps your fountain protected from the mosquitoes. Each tablet will treat 50 gallons of water.

Although this is a synthetic solution, you don’t have to fret since this is an EPA-approved product.

However, we’re not sure if this is safe to use on swimming pools. If you want to keep mosquitoes away from your pool, it’s better to treat it with chlorine.

✔️Lasts for up to 60 days
✔️Safe to use on feeding troughs and fish ponds
❌Not ideal for swimming pools

Frequently Asked Questions

Q: Do water fountains attract mosquitoes?

A: Water fountains don’t attract mosquito per se. However, if the water is left standing for days, it will become a breeding ground for mosquitoes. Shallow water fountains are the preferred egg-laying spots of mosquitoes since their larvae can easily float and reach the surface.

Q: Should I leave my water fountain on all the time?

A: Most water fountains built outdoors are made to last 24/7 operation. If you want to run it to avoid mosquitoes, we see no problem. However, you should know that continuous operation means that the fountain will use more energy. Also, you should refill the water once a large amount has evaporated.

Q: Can I put vinegar in my water fountain?

A: Yes! Vinegar is an affordable solution to keeping the mosquitoes off your fountain. Anyway, it may give off a sour scent which is more evident in large fountains with more water. It’s a matter of personal choice.

Q: How do you keep mosquitoes from breeding in a fountain?

A: The most common practice, especially on commercial fountains, is placing BTI dunks. These are safe, even for fountains with fishes. The microorganisms on the dunks will feed on larvae and arrest the mosquito population on the fountain.

Q: Can I put bleach in my water fountain?

A: If you’re thinking of using bleach and chlorine to keep mosquitoes off your fountain, you should think twice. Most fountain pumps aren’t made to work with high levels of chlorine and abrasive bleach. As much as these chemicals work, it will also damage the fountain in the long run.

Final words

Knowing how to keep mosquitoes out of water fountains is the first step to arrest their population. You have to stop these insects from laying eggs and using your fountain as their breeding ground.

The Summit BTI dunks are very effective for this purpose. As long as you use it right, your fountain will be mosquito and larvae-free all year round.

What do you think of this? Let us know below!