Pool Chemistry

The ABC’s Of Understanding Pool Chemistry

Spring will be here before you know it. That means it will soon be time to start thinking about opening your in-ground swimming pool. Are you unclear as to what all those chemicals do? You know that your pool needs chemicals, and at Hawaiian Pool Builders, we will make sure you get exactly what your pool needs. Here’s your ABC’s to understanding pool chemistry.

There are five chemical levels that every pool owner needs to keep track of:

FC – Free Chlorine – A sanitizer which keeps your pool water safe and germ-free. Chlorine must be replenished constantly.
Maintaining an appropriate FC level is the most important part of keeping your water balanced. It is important that you do not let it to get too low, or you are at risk for algae growth. If this reaches zero, or you show signs of algae, your pool needs to be treated.

pH – Acidity/Basicity – Needs to remain in balance to prevent irritation, and protect your pool equipment. This level should hold a range from 7.2-7.8
pH indicates how acidic or basic your pool water is. If this is the first year enjoying your pool, your ph should be tested daily. Once you gain experience with your pool, less frequent monitoring may be appropriate, depending on your pool’s typical rate of pH change. Levels of 7.7-7.8 is ideal, but, if a range of 7.2-7.8 is fine for swimming.

TA – Total Alkalinity – Appropriate levels help keep the pH in balance to prevent irritation and protect your pool equipment.
Total alkalinity indicates the water’s ability to buffer pH changes. Buffering means you need to use a larger quantity of a chemical to change the pH. At low TA levels, the pH tends to swing around wildly. At high TA levels, the pH tends to drift up.

CH – Calcium Hardness – Safe levels help prevent plaster damage. High levels can cause calcium scaling. Typically, a range from 220-350 ppm is recommended, though if your pool is a vinyl pool, that range should be lower.
Calcium hardness indicates the amount of calcium in the water. Over time, water with low calcium levels will tend to dissolve calcium out of plaster, pebble, tile, stone, concrete, and to some extent fiberglass surfaces. You can prevent this from happening by keeping the water saturated with calcium. In a vinyl liner pool there is no need for calcium, though high levels can still cause problems. A gunite pool without a salt-water generator system (SWG) should have CH levels between 250 and 350 if possible. With a SWG, CH should be kept between 350 to 450. Calcium helps fiberglass pools resist staining and cobalt spotting. If you have a spa you might want to keep CH at least 100 to 150 to reduce foaming.

CYA – Cyanuric Acid – Protects chlorine from sunlight and determines the required FC level. This level should range from 30-50 ppm. If your pool is a salt-water, this level should range from 70-80 ppm.
Cyanuric acid, often called stabilizer or conditioner, both protects FC from sunlight and lowers the effective strength of the FC (by holding some of the FC in reserve). The higher your CYA level, the more FC you need to use to get the same effect. It is important to know your CYA level, so you can figure out what FC level to aim for. If you don’t have a SWG, CYA is typically kept between 30 and 50ppm. If you have a SWG, CYA is typically kept between 70 and 80ppm.

There are four other chemical levels that come up frequently enough that you should at least familiarize yourself with. They are:

CC – Combined Chlorine – CC over 0.5 ppm indicates a problem.
Combined chlorine is an intermediate breakdown product created in the process of sanitizing the pool. CC causes the “chlorine” smell many people associate with chlorine pools. If CC is above 0.5ppm, you should SLAM your pool. CC indicates that there is something in the water that the FC is in the process of breaking down. In an outdoor pool, CC will normally stay at or near zero as long as you maintain an appropriate FC level and the pool gets some direct sunlight.

Salt – Salt is required with SWG. Salt can also be added to the water to enhance the subjective feel of the water.
For a SWG, check the manual for the correct salt level for your unit. This level will typically around 3,000, but different models vary. For improved water feel without a SWG, try levels around 2,000ppm. These levels are less than one tenth of the salt level in ocean water, which has around 35,000 ppm of salt. People vary in their ability to taste low levels of salt. A few people can taste salt levels as low as 1,000ppm, others not until 3,500ppm or more.

Borate – Borates are an optional enhancement that helps control pH drift, keeps algae in check and provides various subjective water quality/feel improvements.
If you are not intentionally using borates, there is no need to test for them. If you are using them, we recommend you keep your level between 30 and 50 ppm.

Phosphate – Phosphates are sometimes removed from a pool as a way of keeping algae in check.
Phosphate reducers are specialty chemicals used to remove phosphates from pool water. They are typically salts of aluminum or lanthanum which, when added to water, produce insoluble phosphate compounds which are removed through filtration, vacuuming or both.

There you have it, the ABC’s of understanding pool chemistry. The experts at Hawaiian Pool Builders are available to answer all of your questions concerning your pool, and ensure that you are getting exactly what your pool requires. Once you know what you need, you can walk right next door to our retail store to purchase everything at one time. Feel free to call and make an appointment, or stop in, we are here for you. Of course, we also have service and maintenance packages available for you. That way, you can simply lay back and enjoy your pristine pool.

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