A common pool problem
All About Algae
Algae is the most common pool water problem only because it is the most visibly obvious one. Algae in itself is not dangerous — in fact, it is the main ingredient in many health supplements and tablets. Algae brings danger in that it converts sunlight into food, releasing wastes that become the feeding grounds for unwanted and harmful bacteria and other micro-organisms.
There are well over 20,000 species of algae, only a few of which are encountered in swimming pool water. Algae is almost constantly entering the pool, and as soon as the sanitizer level drops too low, the algae begins to take hold and multiply. It takes as little as a few hours on a warm sunny day for your sparkling pool to develop an algae problem. The algae “spores” found in the air are from algae that have dried out (at a nearby stream, from a neighbor’s pool, etc.) and become airborne with the breeze.
Types of Pool Algae
Algae in swimming pools is often referred to by its color.
How to remove algae from pools
Preventing pool algae
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Total alkalinity is a measure of the total amount of dissolved particles in the water whose pH is higher than 7.0. Total Alkalinity (TA) should usually be kept at 80 – 120 ppm, though in high alkalinity waters this is often hard to achieve without resulting in an abnormally low pH. When your TA is low, the following can occur:
Raising low total alkalinity
Lowering high total alkalinity
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Chloramines are the result of insufficient free chlorine and usually result in a strong chlorine odor in and around the swimming pool. Chloramines are formed as a product of nitrogen and active chlorine (hypochlorous acid — HOCl). The nitrogen is most commonly introduced into the pool water as ammonia in the form of sweat and (unfortunately) urine.
Chloramines (combined chlorine) are poor sanitizers and have a gaseous tendency. The presence of chloramines (and dichloramines/trichloramines in particular) cause the following physical symptoms:
In addition to these, the pool has a tendency to discolor, becoming milky or green with algae due to the low sanitizing ability of the combined chlorine.
Testing for combined chlorine in pool water
Destroying combined chlorine compounds
Common causes of
Cloudy pool water
How to clear up cloudy water
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Metals in pool water
Fill or ground water can cause copper, iron, and manganese can find their way into the pool. The copper and iron can also be from metals in accessories like the pump or heater that are corroding due to improper water chemistry.
If the pool’s pH, total alkalinity, or calcium hardness level is low, then the water tends to be corrosive and the “rusting” of metal parts in the pool is greatly increased. Another common source of copper is copper-based algaecides. The cheaper ones often supply copper ions rather than complexes and, if too much is used, will result in green pool water.
If the water changes color after chlorine (or any other oxidizer) is added, the swimming pool water probably contains a metal.
What happens if I have high levels of metals?
Shock the pool to oxidize the metal, which then settles out of solution and looks like rust. The rust can easily be vacuumed out of the pool. Add a sequestering or chelating (ˈkēˌlāt) agent, which forms complexes with the metal and prevents it from being oxidized by the chlorine.
Prevent repeat problems: If the source of the copper or iron cannot be established or if it cannot be avoided, regular addition of a chelating agent or sequestering agent (metal out products) will ensure that any new metal arriving in the pool water will be held in an inactive complex.
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Pool Water ph
One of the biggest parts of pool care is maintaining the chemical balance in your pool. Chemistry is key to keeping your pool clean, as well as making it a safe, pleasant environment for swimming. Chemicals like chlorine are used to keep algae and bacteria under control, while chemicals like muriatic acid keep the pH levels of your pool’s water balanced. You’ll need test strips and a drop kit to check and maintain chlorine and pH levels. It also is important to keep a consistent volume of water in your pool; a lower-than-normal level can make your chemicals too intense and a higher-than-normal level can dilute them and make them ineffective. Improper water levels will also have detrimental effect on filtration and circulation.
The ideal range for pH in swimming pool water is 7.0 – 7.6. The pH of our eyes is typically 7.2 – 7.4. In our experience, if the pH is kept at the same level as that in our eyes, the side-effects of burning red eyes is kept to a minimum. The ability of chlorine to disinfect at this level is also optimal.
What is pH?
Lowering high pH
Raising low pH
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Total Dissolved Solids
Total Dissolved Solids (TDS) is the measure of the total of all the soluble substances dissolved in the water.
For swimming pools, the maximum recommended TDS level is 1,500 ppm. Values above this can lead to various problems with your pool. Some of the issues include: cloudy pool water, staining of the pool surfaces, scaling, hard water, a salty taste, algae growth and irritated skin and eyes.
In swimming pools using salt-chlorine generators, the large volume of salt added radically increase the TDS level. Sunscreen, sweat, debris and other chemicals also increase the TDS level and create a residue in your pool.
The TDS should be checked once every six months. If the pool water has become saturated with contaminants and the TDS level confirms this, the pool should ideally be drained and refilled with fresh water. There is no method to reduce TDS effectively without replacing some or all of the swimming pool water.
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The measure of all the dissolved minerals such as calcium, magnesium and sodium is known as total hardness. Regarding pool water chemistry, it’s known as calcium hardness. High or low levels of calcium hardness can result in issues, so the recommended level for calcium hardness is 200 – 400 ppm. To find out the hardness of you swimming pool, you will need to perform a calcium hardness test.
You can increase the calcium hardness level by adding calcium chloride. If the swimming pool suffers low hardness due to the low quality of the fill water, calcium hypochlorite should be added. You can perform a calcium hardness test if you suspect insufficient levels.
High calcium hardness results in scale formation on the pool surfaces as well as scaling in the pipes, plumbing and filter. High calcium levels will also cause sore eyes of swimmers.
If the calcium is a result of pool chemicals, draining some or all of the pool water will lower the calcium hardness level. If the cause is the fill water, commercial hardness reducers or chelating agents will bond with the calcium to keep it trapped in solution.