Chemistry can be difficult to understand and water chemistry is no different. People think they can just dip their finger in a swimming pool and figure out the pH and chlorine content, it really doesn’t work that way.
We, at Sutro, strive to make chemistry simple – so you can focus on the things that matter most with your backyard. Spending time in the water, and spending time with people you love … in the water.
We’ve put together a quick simple list of the ‘buckets’ of chemicals that are in the market. Everyone may be trying to sell their own version of a “magic bullet”, however, sticking to the basics and being consistent will keep most pool (and spa) owners in the clear.
Sanitizers are products that keep your water safe. Think of them as chemicals that kill bacteria and viruses.
Sanitizer used to maintain chlorine or bromine residual in your water. One of the most important steps in maintenance! Don’t lose your whole weekend to pool trouble, spend a few minutes throughout the week. Chlorine and bromine are approved to kill both bacteria and viruses. Having one or the other is essential to pool and spa water according to the CDC: Disinfection & Testing.
Product names can include liquid pool chlorine, pool shock, chlorine tablets, granular chlorine, brominating salt, and bromine tablets.
A secondary sanitizer that is also used as your oxidizer to “shock” your water. This cleans up anything that the sun, your UV, or your ozone is not keeping up with cleaning. In the pool store, these will be your shock products.
Product names can include liquid pool shock and pool shock.
Note: Be wary of what other measurements will increase from some of these products such as cyanuric acid or calcium hardness.
Oxidizers are products that reduce the build-up of bi-products, such as combined chlorine, from sanitizing your water. This can include equipment, such as UV and ozone treatment, specific chemicals such as Chlorine-free pool shock products, as well as your secondary sanitizer if it is a chlorine product.
pH up, or its many name variants, is a base to increase the pH of your water. A balanced pH is important for sanitation as well as protecting your pool and equipment! The most common base used for pools and spas is sodium carbonate, which is found in most pH up, plus, or increaser products. The sanitizing agent is actually less effective the more out of bounds you are here.
pH down is an acid to decrease the pH of your water. The two most commonly used are sodium bisulfate also known as “dry acid” and hydrochloric acid also known as “muriatic acid”. These acids can also be used to lower your water alkalinity.
To increase the alkalinity of the water, alkalinity up, alkalinity increases, and other products in this category are used. These most commonly contain sodium bicarbonate. pH and alkalinity are very closely tied together because the water alkalinity is helping keep the pH stable. This APSP Alkalinity Fact Sheet will give you some more details on that.
Stabilizer or Conditioner
This product is often called a stabilizer or conditioner, but the active ingredient is cyanuric acid. This time we’re not talking about your pH, but your chlorine! In the same way, the sun helps break down sanitizer bi-products, it is also breaking down your chlorine. To maintain your chlorine in your pool you need to protect it from the sun! There is a balance to maintain between how much cyanuric acid is in your water, too much can hinder your chlorine from doing its job as effectively. See the APSP Cyanuric Acid Fact Sheet for details.
Calcium hardness adds calcium to your pool to prevent plaster damage to your pool. However, too much calcium hardness can cause calcium scaling, or calcium deposits, to form on plaster and other surfaces. Some water sources already have some calcium hardness present, so it’s important to test your water before adding any additional calcium hardness. Take a look at how Pool Water Hardness and Alkalinity play together.
Salt, not your table salt, but still sodium chloride. This is only required for saltwater chlorinators, also called saltwater chlorine generators (SWG). The SWG uses electricity to convert sodium chloride in water into sodium hypochlorite. Basically, taking care of your residual chlorine for you once setup! How APSP Electrolytic Chlorine Generators work is a good read if you want to understand the process.
Metal sequestrants are used if the metals in your pool are too high, mainly iron and copper. Iron is naturally present in some water sources and can cause staining. Copper is included in some pool products such as algaecide and mineral systems. Copper can also cause metal stains and is the real culprit behind hair turning green in pools. Metal sequestrants provide some measure of protecting your pool (and your hair) without requiring you to replace some of the water to bring levels down.
Algaecides are so common that they should be mentioned. Simply, if you are using all the above chemicals properly you’ll never have to add any to your water. They can help deal with algae, but chlorinating will do just as well. So try to stick to a steady maintenance schedule to avoid surprises.
Removes some phosphates from water, which serve as food for algae. Similar to algaecides, by regulating the chlorine or bromine in your water, phosphate remover should not be required in most cases.
Clarifiers are used to remove solid particulates or suspended solids in water. In most cases, your pool or spa filter should take care of these. So regularly check your filter pressures to determine when a backwash, cleaning, or new cartridge is required. Also, make sure your turnover rate is about 4 times per day. This basically ensures most of the water in the pool has passed through the filter at least 1 time per day. More information on the Disinfection: Content Turnover Rate is good to know.
A Better Pool Life Through Chemistry
We hope this brief run-through of the baker’s dozen of pool chemicals give you a better idea of what you’re putting in your pool. At last count, there are over 5,000 different brand names and formulas for pool chemicals. All of them will have one of these baker’s dozen chemicals in them. The next time you buy a pool chemical, take a look at what’s in it and see if we’re right.