Get rid of water bugs in the pool as they can bite swimmers with a sting and swelling similar to a bee sting.
Water bugs are revolting cockroach-like creatures that take up residence in your pool. They can breed quickly and are resistant to pesticides. After killing off an infestation they can suddenly reappear a few weeks later making them a challenge to eliminate.
Finding water bugs in your pool can be frustrating and disappointing. It can happen to well-maintained pools with clear water. But there is no point getting upset. Let’s get rid of the water bugs and make your pool swimmable again.
Table of Contents
What are Water Bugs?
There are two types of water bugs that inhabit backyard swimming pools. And you need to identify which species you have in the pool before you can eliminate them.
Water Boatmen
These bugs have a long, oval-shaped body that give them the name boatmen. They are named “water boatmen because they have forelegs shaped like oars covered with hairs for traction in the water.
These insects have wings and simply fly into your backyard and take up residence in the pool.
Water Boatmen have a dark top and light-colored bottom side for camouflage making them difficult to see in the water.
They swim right side up on their belly whereas backswimmers swim upside down on their backs. This is the way to identify each species. Does it swim on its belly or its back?
They are not dangerous to humans as they are primarily herbivorous feeding on algae and sometimes mosquito larvae. Usually, when they inhabit your pool it’s because your pool is not as clean as it should be and has algae growth.
They do not bite people but you just want to get rid of water bugs in the pool.
Backswimmer
Water boatmen are harmless to people but backswimmers will bite people. The bite will feel like a bee sting and can cause swelling.
Backswimmers look similar to a small cockroach swimming upside down in the pool. They are found all over the world and named for their ability to swim on their backs upside down in the water. They are lighter than water making them easily float on or just under the surface.
Usually, they grow to between 5mm and 16mm in length.
They are counter shaded as the light-colored back is difficult to see from below and blends into the surface and sky. The underside is darker and when viewed from above blends in to the color of water making it difficult to see,
The backswimmer will eat boatmen and other insects. So, when you discover these water bugs you need to eliminate them as soon as possible.
Backswimmers have wings and can simply fly into your backyard.
Why Do I Have Water Bugs in My Pool?
Generally, you will only have water bugs in your pool for a few reasons.
- the water chemistry is out of balance
- there are algae in the water or on pool surfaces
- the pool water is stagnant
- the skimmer box is not functioning correctly
- the pool pump is not operating long enough each day
- the chlorinator is not generating enough chlorine
- there is a freshwater pond nearby
Water bugs need a food supply in the pool to survive.
The most common food supply for herbivorous water boatmen bugs is algae.
There will only be backswimmers in the pool when there are other bugs for the backswimmers to feed on.
How to Get Rid of Water Bugs in the Pool
Detergent
The secret of how to get rid of water bugs in the pool is dishwashing detergent.
Applying a ¼ cup of dishwashing detergent into the middle of the pool will kill water bugs. The detergent will spread over the entire surface of the pool creating a layer of soap suds.
The layer of detergent prevents the water bugs from breathing which kills them.
Leave the detergent in the pool for at least one day. It will not harm the pool or equipment.
Keep the pump turned off for the day.
Now it’s time to clean the pool and remove the dead insects.
Note: Some people recommend using oil instead of detergent. I do not recommend oil as it is messy and difficult to remove from the pool.
Skim the Pool Surface
Get your skimmer net and skim the surface of the pool to get rid of as many water bugs as possible. Dump the contents of the net in a bin and spray with insecticide to kill them.
Clean the Skimmer box
The skimmer box contains a removable plastic filter basket that traps larger items of debris such as leaves, flowers and insects that are floating on the surface.
I recommend the use of skimmer basket filter socks when you have water bugs in the pool. The bugs are trapped in the filter sock and won’t clog up your cartridge or sand filter. Otherwise, you will need to clean the filter as well.
Turn the pump valve to drain so that the surface of the pool is drained away when you run the pump. The water can be drained to the bottom level of the skimmer box. This will remove the layer of detergent floating on the top of the pool surface.
Run the pool pump as normal.
Empty the skimmer basket frequently to ensure free flowing water to the pump.
When the water level has dropped to the bottom of the skimmer box turn off the pump.
Turn the pump valve back to filter.
Add water to the pool to bring the level halfway up the skimmer weir flap.
Swimming pool skimmers function properly when the water level is halfway up the weir flap. If the water is too high floating debris is not drawn into the skimmer box. If the water is too low the skimmer box may run dry damaging the pump motor.
Run your filter as normal again.
Read more about How a Pool Skimmer Box Works
Brush Your Pool Surfaces
Brush the pool surfaces because automatic pool cleaners and vacuum heads don’t clean well around steps, ladders and in corners.
You need to remove any algae and water bug larvae from the pool surfaces. If there are no larvae you won’t be re-infested in a few weeks. And if there are no algae there is no food supply for hungry water bugs.
The extra effort will reward you with a cleaner pool that is not likely to be invaded by algae or water bugs.
Vacuum Your Pool to the Drain
The skimmer box only removes dirt and debris floating on the surface of the pool. Once dirt and other contaminants sink to the bottom you need to vacuum the pool. And the longer dirt is in your pool the slimier and grimier it becomes. It attaches itself to every surface and is more difficult to remove. Even vacuuming doesn’t remove all of it.
Vacuum the bottom to waste so algae and dirt is deposited in the drain not your filter.
This saves you constantly cleaning your filter and prolongs its life span.
It’s a simple matter of turning a valve on your filter to waste and afterwards back to the filter position.
You will need to top up the pool from the garden hose for the water lost to the drain.
Clean the Pool Filter
The filter has a pressure gauge indicating the water pressure inside the filter when the pump is operating.
When the pressure increases above a threshold (usually indicated on the gauge) the filter has become dirty and needs cleaning.
Pool filter cartridges are simply removed from the filter housing and pressure washed with a garden hose. Remember to turn off the pump before opening the filter housing and turn it back on again when the task is complete.
Sand filters are backwashed into the drain by operating the multiport valve located on the side of the filter.
If the water pressure is still high after cleaning your filter, then you need to replace the cartridge (or sand) in the filter.
Recommendation: I recommend having two filter cartridges. When the filter needs cleaning swap out the filter cartridge element with the clean one so your filtration system can operate immediately. Clean the dirty cartridge, dry and store.
Run the Pump for 8 Hours per Day
The pump and filter must run long enough (normally 8 hours) to process all the pool water each day. That is, the pump must turnover all the water in the pool on a daily basis to ensure the pool water is clean.
You can split the timer into two operating periods so that the pump runs twice a day.
Run the pump from 9am to 3pm (6 hours) and 8pm to 10pm (2 hours). These 8 hours will save you money as you are using off-peak electricity. During the day you may be using solar generated electricity. These times will ensure the pool is adequately filtered and sanitized but also not annoy your neighbors with pump noise in the middle of the night!
Test the Pool Water
Testing pool water should be performed weekly and is the most important component to your pool maintenance routine.
I recommend pool test strips as they are the easiest and quickest to use.
Test for pH, free chlorine, cyanuric acid, total alkalinity, calcium hardness, total dissolved solids, copper, iron and salinity (salt water pools).
Balance the Pool Water
Here are the basic chemical indicators and desired levels for a backyard freshwater or saltwater pool. If your pool water is maintained within these parameters your pool will always be clear and safe for swimming.
pH Level 7.2 – 7.6
Free Chlorine 1.0 – 3.0 ppm
Cyanuric Acid (Pool Stabilizer) 30 – 80 ppm
Salinity 2700 – 4500 ppm
Total Alkalinity 80 – 120 ppm
Calcium Hardness 200 – 400 ppm
Total Dissolved Solids (TDS) 3000 – 6000 ppm
Depending on the results of your pool water test, adjust the chemical balance of the water to maintain the above ranges.
Shock to Get Rid of Water Bugs in the Pool
Shocking the pool boosts the normal level of chlorine to ensure you have killed bacteria, contaminants and water bugs in the pool.
However, this time use 3 or 4 times your usual shock dosage.
Repeat the dosage in a couple of days to ensure all water bug larvae are killed.
Dissolve the shock chemical in a bucket of water.
Pour the bucket of water around the whole pool to ensure the shock reaches all parts of the pool.
Run the pump for several hours.
The best time of day to add shock to your pool is in the evening after you have finished using the pool for the day and just before the pump is due to operate.
Adding the shock after the sun has gone down will ensure it works all night as there is no ultraviolet light to reduce its effectiveness. And at night the cooler water reduces chlorine evaporation from the water.
Make sure the pump is going to run for at least 4 hours to thoroughly mix in the shock chemical.
Note: You cannot swim in a pool that has been shocked until the chlorine level returns to normal (below 3ppm).
Usually, the next day your pool is ready for swimming again.
Cover to Get Rid of Water Bugs in the Pool
Algae spores are carried in the air and blow into the pool.
Water bugs fly around the neighborhood looking for a nice place to live.
Pool covers keep algae and water bugs out of your pool.
Clean the Salt Water Chlorinator Cell
It’s important that the pool is well chlorinated to ensure algae cannot grow.
Saltwater chlorinators are low maintenance units however saltwater chlorinator cells require cleaning every 12 to 24 months.
Please read the manufacturer’s instructions for your model of saltwater chlorinator to determine how frequently the cell requires cleaning.
Please read our article How to Clean a Saltwater Chlorinator Cell
Clean Around the Pool
Now you have cleaned the pool you will need to clean the pool coping, deck, patio and pathways. This ensures that algae cannot grow anywhere near your pool.
The best way to clean these hard surfaces is with bleach (alkaline) or an acid wash. I prefer bleach as it is very inexpensive when purchased from a supermarket.
Dilute the bleach in a bucket of water. Use two cups of bleach to a bucket of water. Brush the bleach over the hard surface with a stiff broom. Leave it to work for ten minutes then rinse away with the garden hose.
Get Rid of Water Bugs in the Pool Permanently
Clean the Pool
As prevention is much better than trying to fix a problem, I recommend keeping your pool as clean as possible.
The pool still needs brushing, suction cleaning, chlorination, filtration and shocking even when not in use.
Remember to shock the pool at night to give the chemicals the best chance of working as there is no sunlight to break down the chlorine. This will also help prevent water bug invasions which mostly occur at night.
Algaecide
When your pool is clean add algaecide to the pool water. Algaecide will help prevent algae growing in the water. If there is no algae there are no water bugs.
However, once algae have invaded the pool it will not help to eliminate algae from the water. Only strong chlorine will eliminate algae.
Run the Filter for 8 Hours per Day
If the filter is not running long enough the pool water becomes stagnant. Water bugs love stagnant dirty water.
Run the filter more. If you have water bugs run the filter 24 hours a day until the bugs are gone. The water bugs cannot feed and swim properly in moving water.
Cover the Pool
The advice I give to every pool owner is to cover their pool when not in use.
Water bugs still live in the water during winter. They have even been found to survive under ice in frozen ponds and lakes.
So, unless you live in a tropical region, once the swimming season is over covering the pool makes sense. A pool cover will keep out insects and keep the pool a lot cleaner during winter.
Covering the pool at night with a solar blanket will keep out water bugs and retain heat in the water for a higher water temperature the next day.
No Pool Lights
Swimming pools look so nice at night when illuminated by pool lights.
However, those glowing underwater lights are attracting the neighborhood insects over for a party in your pool.
Maybe it’s best to only keep the lights on for only a few hours and always turn off before you go to bed. Purchase a timer switch if you don’t already have one.
Shock the Pool Frequently
Shocking the pool more frequently can help to prevent water bugs invading the pool. However, you will need to use 3 or 4 times the normal shock dosage to get rid of water bugs.
Use a chlorine-based shock. Non-chlorine shock will not kill algae and water bugs.
Conclusion
If you have a freshwater lake or pond near your home, you may have problems with water bugs invading your pool. Waters bugs like stagnant water containing algae.
First the herbivorous water bugs will arrive to feed on algae in your pool. Secondly, backswimmers will arrive to feed on the herbivorous water bugs.
The best way to get rid of water bugs is to add dishwashing detergent to the pool. The detergent creates a layer of oily film over the surface preventing water bugs from breathing. The detergent should kill them quickly so you can clean out your pool the next day.
Follow our pool maintenance routine to ensure your pool remains sparkling clean and never infested with water bugs again.
