House Grail is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

How to Kill Mosquito Larvae in Your Pool: 11 Tips & Tricks

Mosquito Larvae

Mosquitos are a major nuisance for a lot of people, but because they congregate around bodies of water, they can be especially troublesome for pool owners. They lay eggs in water, and these eggs develop into larvae when they rise to the surface before maturing into pupa and eventually into adult mosquitos.

While the larvae itself is not necessarily harmful to humans, and it can seem difficult to get rid of the larvae once it is in a pool or other body of water, killing the larvae before it has a chance to mature is easier and more efficient than attempting to kill the mature mosquitos.

Below are 11 tips and steps to help combat or kill mosquito larvae in and around your pool.

divider 1 The 11 Ways to Kill & Prevent Mosquito Larvae in Y0ur Pool

1. Maintain the Pool

pool cover roller
Image Credit: Irina Borsuchenko, Shutterstock

While it is true that some mosquitos prefer nutrient-rich or stagnant water, some will still live around, drink from, and lay eggs in clean water. Ensure that your pool is well maintained by maintaining its pH level, and skim and clean the pool often.

2. Chlorinate and Disinfect

Chlorine can kill mosquito eggs before they become larvae, but the act of killing them will effectively use the chlorine reserves in the water. As such, you may need to add chlorine to the pool more often and test for chlorine levels regularly. To kill existing larvae, it takes a lot of chlorine, and this can be dangerous for swimmers, so if you are going to chlorine shock the water, ensure it isn’t used for some time after. Disinfectants can also help kill eggs and larvae, and disinfecting your pool should be a regular activity to ensure it stays clean.

3. Water Circulation

Rain is falling in a wooden barrel full of water in the garden
Image Credit: Bianca Grueneberg, Shutterstock

Another important part of pool maintenance is running the pump. Running the pump oxygenates the water and helps remove some bacteria. It can also disturb mosquitos and their eggs and larvae while in the water. Especially during the summer months when mosquitos are laying, run the pump every few hours to ensure good water circulation.

4. Use a Pool Cover

A pool cover can prevent mosquitoes from gaining access to the water in the first place and it helps keep dirt and debris away from the water. Choose a cover that really does cover the pool because it only takes a small gap or a small amount of accessible water to leave you with a mosquito problem.

5. Get Rid of Standing Water

Featured image credit: FotoshopTofs, Pixabay

Pool covers are beneficial, but they also bring their own risks, and you will need to choose carefully to ensure you choose a suitable one for your requirements. Some covers need their own pump, which effectively removes water that pools on top. Alternatively, you will have to find some way to remove the water and prevent it from stagnating. You should also look for other areas where pool water might be collecting. For example, in any ditch or hollow around the pool wall.

6. Use Ovitraps

Ovitraps are specifically designed to attract pregnant or gravid mosquitoes. They contain a relatively small amount of stagnant water and have a moist lip where mosquitoes lay their eggs. The eggs slide through a mesh and into the water and, by the time the larvae mature, the mosquitos are too large to get back out through the mesh, so they will die. Buy or make a couple of ovitraps and place them in areas close to the pool to try and divert the pests away from your swimming water.

7. Use Mosquito Dunks

Mosquito Larvae
Image Credit: Napat, Shutterstock

These dissolving rings are placed in the pool and contain bacteria that mosquito larvae feed on. As well as being an attractive food source, BTI is also toxic to larvae and kills them. They are generally considered safe for people and other wildlife, and you shouldn’t need more than two or possibly three in the pool at a time.

8. Add Methoprene Granules

An additional option is the use of Methoprene granules. These are granules that mix into the water, dissolve, and cover the entire water area. One application usually lasts around a month, and Methoprene granules are considered safe for humans and other wildlife.

9. Apple Cider Vinegar

Image Credit: focal point, Shutterstock

Apple cider vinegar is natural and there is a chance you have some around the house. It isn’t as strong and won’t last as long as Methoprene granules, and it may make the pool smell a little vinegary, but it is an alternative to the granules and has proven effective for a lot of people.

10. Scoop Up the Dead Larvae

Whatever method you use to kill larvae, you will be left with dead or dying larvae in your pool that need removing. Your pool filter will eventually get rid of the remnants, but it will have to work overtime and needs more frequent cleaning and refreshing while it does its work. You can help by using a robotic cleaner or by getting a skimmer net and doing the work manually.

11. Maintain the Garden

Mosquito Larvae
Image Credit: SIRITAT TECHAPHALOKUL, Shutterstock

If you’re having to endure swarms of mosquitoes while you’re swimming, the larvae may be elsewhere in the garden. Keep your garden clean and well maintained, paying particular attention to cutting back overgrown hedges. Check birdbaths, water features, and anywhere that water might be collecting in the garden. Even your drains could be a source of stagnant water that is attracting pregnant mosquitos so ensure it is kept clean.

divider 1 Conclusion

Mosquitos are a painful nuisance and can spread disease. Killing them once they’ve matured to full adult size is a serious challenge with them typically proving capable of evading even the most expensive and elaborate traps. Your best bet is to take action when the flying pests are still in their larval state and by following the 11 tips above.

Keep your pool clean and chlorinated to prevent gravid mosquitoes from using the pool to lay eggs, and use safe solutions, like mosquito dunks, for moderate to major problems and a natural solution, like apple cider vinegar, for mild infestations.

Featured Image Credit: Barmgraphy, Shutterstock


Related posts

OUR categories

Project ideas

Hand & power tools