In general, the more you use your pool, the more often you should shock. You may also want to shock your pool after periods of heavy use or weathering in these cases:
If you follow these basic steps, you will be on your way to maintaining a crystal-clear pool and avoiding problematic algae growth. The key is establishing a routine and taking early action if you notice discoloration, cloudy water, scaling, or other signs of trouble. And if you ever find the responsibilities overwhelming, a Pool Service Professional can take care of your pool for you. For a reasonable price, they’ll visit your house every one or two weeks and take care of all the of this stuff for you!
Algae growth is perhaps the most obvious sign of something gone wrong with pool maintenance. Proper maintenance will not only keep your water looking great, but also allow for easy prevention of algae growth. When preventative measures aren’t enough, you’ll need to remove the algae to get back to enjoying your swimming pool.
Free-floating types including green and mustard varieties. These tend to be found throughout the water. Mustard algae tends to cling loosely to the walls of the pool and brushes off easily. It tends to have a yellowish color. Green algae will be visible throughout the water itself and will turn the water different shades of green depending on the infestation.
Black algae is the common name or term given to the dark blue-green algae found growing on pool surfaces. Black algae grows in localized areas such as along one wall, in the deep end, in a corner or around obstacles such as steps indicates an area of poor circulation and poor sanitization.
The growth of both types of algae can be easily prevented by using a quality algaecide as part of a regular maintenance program, and by proper circulation. It takes far less algaecide to prevent algae growth from getting started than it will to cure it once it has occurred.
The regular use of algaecide is also recommended to prevent problems should a failure of the sanitization program occur. Due to the unique nature of chlorine or bromine, these residuals can often be lost very quickly in pools due to equipment or operator error or by heavy rainfall or bather waste demand. Improper water balance will contribute to the ability of your sanitizer to work properly and prevent algae growth. If this occurs without an algaecide present, the rapid growth of algae can occur in a few hours. However, if an algaecide is present, it will act as algae growth prevention (look at it as an insurance program) until the sanitizer system is functioning normally.
In spite of your best efforts, algae problems can occur and require some consideration for proper treatment. When an algaecide becomes necessary, read our guide to pool algaecide types to find your perfect product.
The most common cause of algae growth in a swimming pool is chemical imbalance. If you’re not keeping up with routine maintenance -- including vacuuming your pool and testing and balancing your water -- you’re more likely to struggle with algae issues. And, as any swimming pool owner can tell you, it’s much easier to prevent algae than to try to remove it with pool algaecide.
The most common algae associated with swimming pools is green algae. It is very opportunistic, meaning it will take advantage of any failure in the normal sanitizing program and quickly infest a pool. One will see green algae problems frequently appear overnight following heavy rainstorms. This is because rainstorms actually provide food for the algae in the form of nitrogen. The nitrogen not only feeds the algae but also destroys chlorine residuals.
Green algae must not be mistaken for metal present in the pool water. Metals, especially copper, can give the water a clear green tint. The best way to treat green algae is to prevent it in the first place. Use an algaecide regularly as part of a normal maintenance program. This will prevent algae from growing, even if a failure in the sanitizing system was to occur. It is always easier and more effective to prevent the algae problem than to try and eliminate it once it occurs. When it does occur, treat it promptly. The longer you wait before treatment, the more difficult and costly the result. Select an algaecide that will both kill the existing algae and prevent renewed growth. Follow the label directions and maintain circulation during treatment.
Scrub (again) and vacuum. Take a second pass with your pool brush to remove any remaining green algae. Follow up by vacuuming your pool. This will remove any dead algae that has collected at the bottom of the pool.
Yellow or mustard algae is very similar in form to green algae, but is much slower growing and is deficient in chlorophyll (green pigment) which accounts for its yellow color. It is easily identified by the ability to brush it easily off the pool walls and floor. Because yellow algae grow very slowly, it is also very difficult to destroy. By the time you see it growing in your pool, it has likely been there as long as several weeks. Additionally, since yellow algae is low in chlorophyll which is light-loving, the algae live and even grow in dark areas of the pool such as plumbing and filters. This only compounds the difficulty of control.
To treat mustard algae, care in selection of a proper algaecide is most important. Be certain to select a product made for the control of this unique form of algae. Copper-based algaecides seem particularly well suited for controlling yellow algae. One word of caution: it is not unusual to need to treat yellow algae more than once to bring it fully under control. This again points out the value of preventing the growth in the first place.
Clean everything that has come into contact with your pool water. Wash swimsuits and towels (use bleach!), and make sure to clean and disinfect pool toys and equipment. Remember, yellow algae spores can survive on almost any surface, so this step is critical!
Scrub and vacuum your pool. Use a good pool brush to scrape yellow algae off of your pool walls. Once you’ve removed all of the algae, vacuum your pool thoroughly.
Test and the water. If anything is out of balance – say, the pH is too high or the alkalinity is too low – add chemicals to bring things into line.
Shock your pool. You'll need to use around three times more shock treatment than you'd use for green algae. Run your pool filter for at least 24 hours to ensure that the shock treatment can circulate.
Repeat steps 3, 4, and 5 as needed. Test, brush, and shock your pool as needed, until your pool is 100% algae-free and your water chemistry is balanced.
Pool BuilderFrequently considered the most difficult algae to control is the one we commonly refer to as "black algae". However, it is also likely the easiest to prevent. Black algae typically gains a foothold in areas of the pool that suffer from poor circulation. Areas such as corners, or in certain areas of the deep end, are often identified as places where black algae continues to show up in a particular pool and are then nearly impossible to eliminate. Most often, these areas suffer from inadequate circulation and thus little or no fresh water, sanitizer or algaecide gets to the area with any regularity.
One of the best ways to prevent black algae growth or eliminate it once it surfaces is to correct the circulation problem(s) first. Once it begins forming, black algae develops specialized cells that lock it deep in the pores of pool surfaces. In order to effectively control it, all of its cells, including those deep in the surface, must be killed. It is all but impossible for chlorine alone to get this deep into the pores of the pool.
In addition to the attaching or locking mechanism of black algae, the growing colony also produces a defense mechanism. Outer layers of the colony produce a waxy coat that prevents chlorine or algaecides from penetrating into the colony and killing it. Therefore, the algaecide used should contain a "penetrating" agent. This agent will actually work to help the algaecide penetrate into the pores of the pool surface and cut through the waxy coat with a special wetting action that chlorine does not have.
Break a chlorine tablet in half and rub it directly onto the affected areas. The chlorine treatment will kill the algae’s roots and prevent it from coming back.
Shock your pool. Because black algae is tougher than other types of algae, you might need to use a stronger dose of pool shock. Check the directions on the package or talk to your local pool supply retailer.
Like black algae, this reddish-pink growth isn’t a true algae. It’s actually a type of bacteria – in this case, a slimy bacteria that thrives around PVC pipes and in shady spots on your pool’s surface. Like all other types of algae, pink slime is totally harmless. Unlike black algae, pink algae lacks a protective shell, so it isn’t especially tough to remove.
As cold weather approaches, it’s time to start thinking about winterizing your swimming pool. Winterizing – or shutting down your pool for the season – helps safeguard your pool from costly damage related to freezing water. It’s also a great way to keep your pool clean and ensure that it’s ready to go when the next swimming season rolls around.
Have questions about how to close a pool? New to the whole winterizing thing? Here are a few steps to follow that will make your pool as safe as possible for the winter.
Before you shut down your pool for the season, you’ll want to make sure that your water is balanced. By ensuring that your pool water chemistry is where it needs to be, you can avoid labor-intensive maintenance headaches when it’s time to open your pool up again.
Parts per million – often abbreviated as PPM – is a unit of measurement that tells you how much of a particular substance – such as a chemical or mineral -- is present in water.
pH. This is a measure of the acidity of your pool water. pH level can affect everything from algae growth and corrosion to comfort and cleanliness. It can also affect the effectiveness of the other chemicals in your swimming pool. An ideal pH is 2 and 6 parts per million (PPM). If your pool’s pH is too high or too low, you can use a chemical increaser or decreaser as needed.
Total alkalinity. Alkalinity directly affects your pool’s pH. For example, if your swimming pool’s total alkalinity is too high, your pH will also be too high. If your alkalinity is too low – you guessed it -- your pH will also be too low. You’ll want your pool’s alkalinity to be around 100 PPM.
Calcium hardness. Calcium is always present in swimming pool water. However, when calcium levels are too high or too low, you could be looking at a range of issues such as corrosion and scaling. Aim for a calcium content of 100-400 PPM. Use a hardness increaser to raise calcium levels, and use a sequestering agent to lower your calcium (both products are available in any pool supply or hardware store).
Pro tip: Closing your pool for the season? Consider investing in winterizing chemicals to keep your pool water chemistry balanced and on track. You can visit a local pool professional retailer to learn more.
One critical component of pool closing: chlorine level. Chlorine prevents algae, breaks down bacteria, and keeps your pool clean and fresh. Before you shut things down for the season, it’s a good idea to hit your pool with an extra-powerful punch of chlorine in the form of a shock treatment. Shocking your pool is easy: Use a shock treatment to bring your 10 to 12 PPM. Then, wait a day or two for the chlorine to come down to its normal level, about 5 to 5 PPM.
Remove all skimmer baskets, heaters, slide, wall fittings, vacuums, pool cleaners, ladders and handrails. Clean all items, allow them to dry thoroughly, and store them in a safe, dry place. Once the equipment is out of the way, remove all debris from the pool using a net, a soft broom, or even a leaf rake.
