Our pools are a significant but incredibly worthwhile investment. It is understandable, therefore, to be extremely disappointed when you’re about to take a dip in your pool on a beautiful day only to be greeted by a cloudy green haze that looks about as inviting as a bath of slime.
There’s no doubt that a green pool is an unpleasant surprise, and you’ll probably wonder what went wrong, if it was something you did, and if it’s dangerous to you and your loved ones. There are several reasons your swimming pool water might be green in both inground and above-ground pools, but it’s most likely due to an imbalance in chemicals. The fix, however, will be different depending on which kind of imbalance you have.
At Captains Pool Care, our routine pool cleaning service helps individuals avoid green pools altogether - but if you’re unlucky enough to be dealing with a green pool now, here are the six likely reasons.
While green pool water should not be a cause for alarm, we recommend not swimming in it. With natural bodies of water like lakes or ponds, algae is an essential nutrient for aquatic life. But in swimming pools, water becomes less safe to swim in as the color deepens. As a result, swimming becomes a safety hazard because algae can host bacteria such as E-coli. The darker your water is, the less safe it becomes.
But green pool water is not only a concern for safety; it significantly detracts from the aesthetic quality of your pool and your home. It is unsightly, odorous, and green water can also leave horrendous stains on the walls and floor in your pool. Therefore, for the sake of health, safety, and the value of your home, be sure to treat your green pool water as soon as possible before it gets worse.
As we mentioned, there are a variety of potential culprits to your green water problem. Let’s walk through each one, accompanied by a potential solution.
Algae growth is the most likely reason your pool water is green, and it will be a secondary effect of a majority of the other causes later in this article. Algae are normally kept in balance by water circulation, natural die-off in cool weather, and appropriate chemical balance. If the water circulation or chemicals are off, algae can bloom and cause a pool to be cloudy and green. While you’ll encounter naturally growing algae in ponds and streams, an overgrowth of algae in a swimming pool is more highly concentrated and can be more of a health hazard. Plus, its presence means there’s an imbalance that may also indicate dangerous bacteria growth. As we mentioned, you should not swim in your pool until it’s clear again.
Chlorine is the primary line of defense against organisms that would otherwise grow freely in your pool and pose a health threat. Therefore, if chlorine levels are low, it provides algae an opportunity to get a foothold which will then slowly begin to turn your pool water green. An easy fix is to test your pool water’s chlorine levels and adjust accordingly. Once the proper chlorine levels are established, it will take some time for the filter to clear out the algae, and if the algae has been present for a long time, there’s a chance it’s stuck to the pool walls in which case you’ll have to scrub it off.
Pool filters are tasked with removing dirt, debris, pollen, algae, and other impurities from the water. If your pool is cloudy or green, there’s a strong chance that your pool filter is either not running for long enough periods of time or is ineffective - in fact, your pool filter should be running for eight hours a day or longer if it is used frequently. Furthermore, cartridge filters should be cleaned every six weeks at most and backwashed every one to three months (sand filters should be backwashed every one to four weeks). If this routine pool filter maintenance doesn’t correct the problem, you may need to replace the filter entirely.
The green color of your pool can also be caused by pollen or metal in different respects. Pollen has a naturally yellow-green hue that can cause the pool to turn light green if not properly filtered. On the other hand, high levels of chlorine can cause the metal elements of your pool (such as pool ladders, pump starts, etc.) to oxidize and create a green color. In the first instance, use a pool cover to prevent the entry of pollen when the pool is not in use and be sure to perform routine filter maintenance. For metal oxidation, check your chlorine levels and distill it with fresh water if needed.
If the pH levels of your pool are too high, this can create a chain reaction of problems. Too high of pH prevents chlorine from doing its job; and even if you’re putting the right amount of chlorine in the pool, high pH will in turn allow algae to grow unabated. To remedy this, check that your pool’s pH level is not over 7.8, and if it is, use a pH reducer like sodium bisulfate or muriatic acid to bring the pH down to the correct level.
Phosphates are a source of food for algae, so be sure to check your pool’s phosphate levels as a potential cause for an unexpected rise in algae. If phosphate is indeed out of balance, be sure to increase your chlorine levels.
Finding your pool full of green water is not only frustrating, but it is a potential health and safety hazard. Be sure to check your pool for the likely causes of green water, but if you’re looking for a more permanent solution, consider investing in professional pool cleaning services. At Captains Pool Care, we help numerous individuals keep their pools in pristine condition all year round - that means you don’t have to worry about green pool water ever again! Contact our team to schedule your personalized pool cleaning service today.
