Why Is My Pool Green?
A clean pool with crystal-clear water is every pool owner’s dream — so when something comes along to turn your pool green, it can be frustrating. What is it that is causing this greenish hue across your water? Green algae.
Green algae can take over your pool quickly, thanks to a few different factors.
If your area has seen a lot of rainfall recently, that could be the cause of your green algae problems. The added rainwater changes the chemical balance of your pool water, making it more susceptible to bacteria and algae growth.
Warm water increases the likelihood of algae growth in pools. If you’re going through a heat wave, be sure to keep a close watch on your pool and stay on track with your cleaning schedule.
Water Circulation Problems
Circulation is key to keeping your pool clean. Stagnant water creates an opportunity for algae, bacteria, and other contaminants to take over and turn your pool green. Keep your pool pump clean, in good condition, and running consistently to keep water flowing.
Lack of Maintenance: Cleaning & Chemistry
Neglecting your pool is a recipe for disaster. As a pool owner, it is your responsibility to keep the water clean and algae-free with a regular maintenance routine. This includes vacuuming, brushing, water testing, and chemical balancing.
Non-Algae Cause: Copper Ions
Another reason your pool could be green is if your water has high levels of copper. The chemical balance of your pool can easily be thrown off, causing problems across the board. Regular testing and balancing can help avoid these problems.
Steps for Cleaning a Green Pool
If you are dealing with green algae, it is important to take care of it quickly before the problem becomes worse. Follow these step-by-step instructions from the professionals at ASP - America's Swimming Pool Company:
Brush & Vacuum
Begin by pulling out your pool brush and scrubbing away at every inch of the pool. Make sure you reach the stairs, the walls, and the hard-to-reach corners. This will loosen up any algae that have accumulated on these surfaces, making it easier to remove.
Note that the type of brush you should be using depends on the type of pool you have. If you have a fiberglass pool, use a nylon bristle brush. If you have a concrete pool, use a steel bristle brush.
After you’ve brushed and brushed, it’s time to vacuum. Be thorough and make several passes if necessary.
Test Alkalinity & pH
Next, you need to test the alkalinity and pH of your water. Alkalinity measures the water’s ability to resist a change in pH levels. Your pH levels, on the other hand, measure how acidic the water is. When correctly balanced, these chemicals work around the clock to keep your pool clean and safe for swimming.
Test your levels and adjust as needed. Remember, your pH levels should fall between 7.2-7.8, while your alkalinity should be at 80-120 PPM.
Double or Triple Shock the Pool
Shocking should be a regular part of your pool’s maintenance schedule. This process involves adding chemicals to the water in order to keep it balanced and raise the free chlorine levels.
When working against a green algae problem, a double or triple dose is necessary. The increase in chemicals will kill algae and bacteria. Follow the instructions on the package carefully, and be sure to wear protective equipment like goggles and gloves when handling the chemicals.
Run the Pool Filter
After a double or triple dosage of shock, don’t forget to turn on your pool’s filter. This will collect and remove dead algae and other contaminants, leaving you with cleaner and clearer water.
Repeat Until Clear
If, after all these steps, your water continues to look green or cloudy, repeat the process from start to finish. Continue doing so until the water is clear and you see no lingering traces of algae.
What If My Pool Is Still Green After Shocking?
In some cases, it is possible that shocking your pool will not completely remove the green hue from the water. This could mean that algae were not the culprit to begin with, or that your cleaning process may not have been thorough enough.
Test for Copper
When high levels of copper interact with chlorine, it can turn your water green. Test your pool’s copper levels, and adjust with the help of calcium chloride to restore its clarity.
Retest pH & Alkalinity
If, after brushing, vacuuming, shocking, and filtering, your pool is still green, retest your water’s chemical balance. Adjusting it to the appropriate levels could be just what your water needs in order to fight off the algae and other unwanted contaminants.
Brush & Vacuum More Carefully
Another reason your pool may still be green is simply that it wasn’t cleaned properly the first time around! Go for another round of brushing and vacuuming, taking extra care to reach the entire pool.
Clean, Repair, or Replace the Pool Filter
A broken filter can be the downfall of a pool. Without proper filtration and circulation, your water can quickly become the ideal home for algae, making your green water problem even worse.
Examine your pool filter and carefully clean it. If you notice a need for repairs, try to take care of them as soon as possible. In some cases, you may need to replace the filter completely. While this can be frustrating, a new, working filter will keep the water flowing as it should.
What To Do If Your Chlorine Is High But Pool Is Still Green
You’ve tested and balanced your water — but your pool is still green. Why is that? To understand why this may be happening, it is important to know the difference between total chlorine and free chlorine.
Free chlorine refers to the chlorine that has yet to combine with chlorinated water to sanitize your pool. Total chlorine is the combined level of free chlorine and chlorine that has already combined and sanitized your water.
When testing your water, be sure you’re testing the free chlorine level, as this is the type of chlorine that is capable of sanitizing the pool and killing algae.
Will Baking Soda Clear a Green Pool?
As pool experts, we hear this question a lot. The short answer is no; baking soda will not clear a green pool, as it cannot kill algae. Adding baking soda to your pool will, however, raise your alkalinity and pH levels and can be helpful when dealing with small growths of black algae.
When trying to rid your pool of algae, it’s best to stick to brushing, vacuuming, filtering, and shocking the pool in order to completely rid your water of its green tint.
How Fast Can You Clear a Green Pool?
If you’re planning a mid-summer get-together with friends and family and you wake up to a green pool, chances are you won’t be able to clear the algae away in one day. The average green algae bloom takes between 4-5 days to clear, so it may be best to postpone the pool party until your water is clean once again.
Why Does My Pool Turn Green During Winter
Pool Cover Is Dirty or Inadequate
It’s possible for your pool to turn green even after it has been closed for the season, and this could be because of your pool cover. Your pool cover serves as a layer of protection for your water, keeping pests and debris out during the off-season.
Be sure your pool cover is in good condition, properly installed, and stays clean throughout the winter season to avoid green water.
You’re Opening Too Late
Another reason your pool could be turning green in the winter is that you’re opening it too late in the season! As the temperatures rise, your water begins getting warmer, creating the perfect opportunity for algae and bacteria to grow. Keep an eye on the forecast and plan your opening date accordingly.
pH Should Still Be Checked Monthly
Just because your pool is closed for the season doesn’t mean you can press pause on your cleaning and maintenance schedule. Test your water levels at least once a month, balancing as needed. This will help lessen your chances of opening your cover to a green pool in the spring!
Professional Pool Cleaning Services
At ASP - America's Swimming Pool Company, it’s our job to make sure your pool is crystal clear year-round. If you are dealing with an algae problem, you don’t have to tackle it on your own. Our Green to Clean services will remove algae from your pool in no time. Contact your local team today to request a service and get back to swimming!
Disclosure: While basic pool care is encouraged for swimming pool owners, it is highly recommended you consult with a professional pool service like ASP - America's Swimming Pool Company for any issues like pool algae that arise.