What’s the Right Order to Add Pool Chemicals?

Written by Michael Dean
June 12, 2024

pool chemical order

Any pool owner knows that there’s a lot of work that goes into keeping a pool clean. One of the most vital aspects of pool maintenance is making sure your pool water is chemically balanced. While it is a tedious task to test and balance the water, it is necessary to ensure it does not become a hotspot for bacteria, oils, or other contaminants.

But when you’re handling chemicals, you must also add them in the correct order. In this article, I’ll cover the basics of what pool chemicals to add to your pool, in what order, and why it’s important.

Main Takeaways

  • Pool chemistry requires the careful and expert balancing of alkalinity, pH, calcium, and chlorine, followed by agents that sequester these chemicals and bind them for longevity.
  • Adding chemicals in the proper order ensures that no volatile reactions occur.
  • Chemicals mixed incorrectly, at the wrong levels, or out of order can cause severe skin and eye irritation. This is why following the correct order and recommended levels for your pool according to safety guidelines is so important.

What’s the Right Order to Add Pool Chemicals?

There is a correct order to add pool chemicals, and you should not switch it up or around. I’ll cover why it’s important to do so below. For now, let’s go over the recommended steps to add chemicals one by one.

1. Alkalinity Adjuster

Alkalinity significantly influences the pH balance of your pool, which is why it is important to add it first. To lay the foundation for properly balanced water, you need alkalinity at 80-120 ppm (parts per million). 

To raise your alkalinity levels, add baking soda to your pool water. And to lower it, you’ll use muriatic acid or sodium bisulfate. Check out my article on how to add muriatic acid to your pool for exact instructions.

Test your water after adding baking soda, muriatic acid, or sodium bisulfate. Low alkalinity can leave the water too acidic, which is unsafe and can cause a burning sensation on swimmers’ eyes and skin. Low alkalinity can damage pool equipment and also render any chlorine added useless.

High alkalinity is not good for your pool water, either. It can make the water cloudy and result in increased calcium levels, which can cause scaling (calcium deposits) on your pool plaster and equipment. It is also tricky to adjust alkaline levels that climb too high, so start low and add in increments while testing to ensure you don’t overdo it.

2. pH Adjuster

PH refers to the degree of activity of an acid or base (alkali) in the water. PH is a vital factor that denotes the health of your pool water. It can be measured on a scale from 0 to 14, with 7 being neutral. Your pool water should have a pH level of 7.2 to 7.6 ppm. If too low, the water will become acidic and may corrode your pool equipment. If too high, the water will become cloudy and neutralize your chlorine.

Adjust the pH of your water using a pH adjuster such as soda ash, sodium bisulfate, or muriatic acid. Soda ash should be used to raise the pH level, and sodium bisulfate or muriatic acid to lower the pH level.

3. Calcium Hardness

Calcium hardness in water is another critical aspect of balancing your water chemistry. If it’s too low, your pool surface could suffer from pitting, etching, and general corrosion. Too high, and you will encounter cloudiness, scaling, discoloration, and staining.

Once added, calcium is more stable than pH or chlorine, so you can get away with testing it less often. However, it should still be a part of your regular pool testing routine. Ideally, calcium levels should be around 200-275 ppm for concrete or plaster pools. For fiberglass or vinyl, keep it at 175-225 ppm.

To raise the levels of calcium, use an agent like calcium chloride. And to lower calcium levels, either replace some of the water or use a pool flocculant.

4. Chlorine

Chlorine is an economical and effective pool sanitizer that oxidizes contaminants such as viruses, bacteria, algae, oils, and dirt. The recommended amount of chlorine in an average-sized pool is 3 ppm. If there is not enough chlorine, it won’t clean the water. If there’s too much chlorine, it hurts the pH of the water, making it more acidic. Use a chlorine neutralizer if you accidentally make the chlorine levels too high.

Chlorine comes in three different forms: liquid, granules, or tablets. If you use liquid chlorine, measure the amount before mixing since it’s easy to add too much liquid if poured directly from the container. If you use granules, dissolve them in a 5-gallon bucket of water first to ensure they dissolve completely before pouring them into your pool. And for tablets, use an automatic chlorinator or a floating chlorine dispenser or directly add them to your pool’s skimmer basket.

5. Cyanuric Acid

Cyanuric acid, or CYA, is a type of pool conditioner or stabilizer. It stabilizes and balances the levels of chlorine in the pool. By stabilizing the chlorine, CYA helps it last longer in the pool under the sun. If your chlorine is unstabilized, adding CYA is heavily recommended. CYA acts as a layer of protection for the chlorine molecules, keeping them safe against UV rays and helping the chlorine last five to six times longer in the pool. A sunny day can kill 90% of the chlorine in just under two hours, so do not skip this step.

6. Algaecide

Algaecide is an often overlooked step but a pretty important one. It acts as a preventive measure against one of the most common issues afflicting pools: algae. Algae takes root regardless of how often your pool is used and should be nipped in the bud ASAP to prevent a full-blown algae bloom or infestation, which is pretty challenging to reverse. Consult a pool professional before adding the appropriate measure of algaecide to your pool for the best results.

7. Salt (If Applicable)

When adding salt to your pool, you must use 99% pure sodium chloride. The quality matters since you will add several bags to your pool, so buy it from your local pool store. If you’re using a saltwater chlorine generator (SWG), check the recommended levels of the system before adding salt to the pool, which on average ranges between 2,700-3,400 ppm, with 3.200 ppm being ideal.

Why Is It Important To Add Chemicals In The Right Order? 

Adding pool chemicals in the correct order is quite important since you are, after all, dealing with substances that can be volatile if mishandled. When you proceed in the correct order, using the recommended levels, you ensure the water is clean, sanitized, and safe for contact with human skin.

For instance, adding the alkalinity adjuster first helps stabilize the initial pH preventing any fluctuations. This makes further adjustments to pH down the line easier. Adjusting calcium hardness before adding your chlorine is a similar stabilizing step to make the water chemistry behave in a more predictable way for the chemicals that follow.

Following the steps correctly allows you to build a foundation of water chemicals. This is vital for a healthy pool, and every pool owner should become familiar with these steps for the proper safety standards and procedures.

What Happens When You Put Chemicals In The Wrong Order?

Mixing chemicals in the wrong order is a surefire way to mess up your pool and possibly even your skin. Certain chemical reactions (like mixing different chlorine types), if added in the incorrect order, can produce toxic fumes or corrosive reactions that can harm your eyes, your skin, or your pool equipment.

For your safety, add chemicals one at a time and test the water before proceeding to the next step. And if it’s your first time adding chemicals to your pool, make sure to put in the correct pool start up chemicals. If you are new to being a pool owner and still have doubts about adding chemicals yourself, I recommend following the advice of a well-known pool professional in your area for the first few times you have to do so.

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Feel free to contact me for any other questions you may need to be answered. And remember, safety first!

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