Testing your pool water at least once a week? Ah hu.

Testing your pool water at least once a week? Ah hu.
Run the pump for 15 minutes in the morning. Aim to get there before noon, as the heat and sunlight during the day can affect the chemicals in the water. If the pool's systems are off, turn them on and wait at least 15 minutes for the chemicals to disperse.

As long as the system remains on for at least 15 minutes, you can collect samples immediately.


Take a sample in the middle of the pool. Stand outside the pool, approach the side, and descend to the surface. You'll want to stay away from any jets or skimmers, as these are where chemicals build up. The middle of the pool is where you can get the most accurate results.


Collect the sample in a cup or bottle. You don't need a lot of water, just cover the test strips or mix with the liquid in the test kit. Have a clean mug or mug in the kitchen. It also works if you have a plastic bottle and is easy to cap if you want to take your samples to a professional.

Make sure to wash the cup or bottle with soap so that the sample is as accurate as possible.

Immerse the collection cup elbow deeply in the water. An easy way to collect a sample is to first turn the cup upside down. Lower your arms until the water reaches your elbows, about 12 to 18 inches (30 to 46 cm) deep. Turn over the cup to collect the water.

Test at least once a week. Pick a day of the week and test the water one day a week. Most home pools can be safely maintained this way. If your pool does not drain during the winter, you will still need to test it weekly.

Ideally, you should test your pool 2 to 3 times a week.

Swimming pool water is not allowed to freeze in winter. Lower the water level until it is below the skimmer and run the pump normally. Stop ice formation to protect your pool and collect samples with ease!

For example, your pH may be too high, but when you add chemicals to lower it, the alkalinity drops too low.

Another example is when your water is green, but treating it with algae doesn't work, you need to know if metals are causing it.

Use a test kit

Buy a water test kit. There are several different types of pool testing kits. Test strips are the cheapest and easiest to use. Make sure the strip is printed with a card or a colored chart on the back of the bottle so you can interpret the results. Once you have the chart, you can buy additional strips instead of the entire kit.

Another variety of tests are liquid test kits. You add the accompanying chemicals to the water and look for a color change. It can be difficult to mix the dyes in the proper ratios and see slight color changes.
The last option is a digital water tester. Dip the end into the sample to get the result. These are accurate but expensive and can fail.


Submerge the test strip for 15 seconds. After this, the strip will change color. Remove the strip immediately, but do not shake off the water. For test strips, you only need a water sample.

For liquid testing, pour a few drops of dye into the water sample. You will need to collect new pool water samples for each dye.

For digital testers, stick the sensor in the sample.

Compare the results with a color chart. The color chart will be located somewhere in the kit or on the back of the test strip bottle. If you buy a 4-in-1, 5-in-1 or 6-in-1 strip, several colored patches on the strip may change. Each corresponds to an individual chemical measurement on your color chart.

Not all 1 strips only test a single element. You need to go to the store and get separate strips for chlorine, pH and alkalinity. Strips for cyanuric acid and water hardness are also recommended.

Look for a pH between 7.2 and 7.8. A water test below 7.2 is more acidic, so if you notice colored stains on metal or corroded pipes, a low pH may be the culprit. Water above 7.8 is more basic, causing chemical deposits on pool gear and preventing chlorine from killing bacteria and algae. Both high pH and low pH water can irritate eyes and skin.

The pH can be raised by adding soda ash, which can be purchased at any pool store. Follow the directions on the label to find out the appropriate amount to add.

The pH level was lowered by mixing with hydrochloric acid.
Test chlorine levels between 1 and 3 ppm. Again, the corresponding patch on the test strip will change color, so read the chart to determine the chlorine level. Chlorine protects against bacteria and algae, so low chlorine can be the cause of green water or disease. Chlorine is highly irritating to the skin.

If your pool uses bromine instead of chlorine, the color on the strip should correspond to a level between 2.0 and 4.0 ppm.

Chlorine tablets are a common way to improve this measurement. Get them to the store and put one in a chlorinator or skimmer basket every week.

Chlorine burns naturally during the day. You can reduce it further by using neutralizing chemicals such as sodium thiosulfate or sodium sulfite.

The target alkalinity is 120 to 150 ppm. Alkalinity can change a lot due to pH, or it can cause a change in pH. High alkalinity causes scaling and cloudy water, while low alkalinity corrodes and stains pools.

Baking soda (sodium bicarbonate) is the main product used to raise alkalinity levels.

Check to see if the cyanuric acid level is between 20 and 30 ppm. Cyanuric acid is usually contained in chlorine tablets, which keep the chlorine in the water longer. It's an acid, so it's probably what lowers pH and alkalinity. It is also important to keep chlorine levels consistent, so a lack of cyanuric acid can lead to low chlorine levels.

Cyanuric acid is added by regularly using chlorine tablets. Adding a product called a stabilizer to the pool store also helps.

To lower cyanuric acid levels, stop using chlorine tablets for a while, then switch to chlorine shocks. For immediate results, drain some water and replace with untreated water.

Choose a calcium hardness rating based on your pool type. For vinyl pools, levels need to be between 175 and 225 ppm. In concrete pools, between 200 and 250 ppm is best. Water that is low in calcium can damage pool walls and linings. High calcium levels can lead to cloudy, scaly water.

Chlorine shock is what increases calcium levels.

To reduce calcium levels, try adding flocculants from your pool supplier. Another option is to drain some water and replace it.


Healing pool water

Calculate the amount of chemicals you need to add. Any product you need can be purchased online or at the pool store.

Add chemicals at night when everyone is out. Allow time for the chemicals to circulate before anyone swims in the water. Immediately turn on the pump for at least half an hour to dispense the chemical.

To keep your pool healthy, run the pump 6 to 8 hours a day. You can do this by turning on the pump at night, spreading the chemical, and having the water ready for testing.

Pour the chemicals into the pool one at a time. Start with 1 chemical and add it to the pool before moving on to the next one. Let the first chemical circulate for a few minutes while the second chemical is prepared. Mixing chemicals directly together can be dangerous.

This also means you should avoid using the same measuring cup for both chemicals unless you rinse out the cup first.

Gradually add chemicals to the pool according to the instructions. Read the package directions first. Chemicals are usually put into the pool after being diluted with water and poured slowly into the pool. In addition, the manufacturer will specify how and how often the chemicals are added.

It is a good idea to test the water 24 hours after adding the chemical. This allows you to monitor changes as you make major adjustments to chemical levels.

Remove metal stains with a household filter and descaling agent. Metal in pool water will not harm swimmers, but will discolor the water and pool lining. Empty the water and treat the stain with a pool stain remover product. Install a pre-filled filter on the hose or connect the hose to a water line serviced by a home water purifier.

Metals will come in all shades of color. For example, copper leaves green stains and turns unwashed blonde hair green. The iron leaves a brown-red stain.


There are test strips to monitor metal levels, but they are expensive.

Clean green water with chlorine. Green water is caused by algae, which can be prevented with chlorine shocks and pills. Dilute gradually in water weekly according to the directions on the package. Afterwards monitor the pool's chlorine levels and watch for water removal as the water level rises.

Green water can also mean dirty filters, especially after adding shock. Remove the filter and rinse it with a hose. After a few days, add some baking soda to the water to clear it up.

Drain the pool when all other methods fail.

Sometimes the easiest way to fix bad pool water is to replace it. Drain and repair any problems with pipes, filters, or other equipment that affects water. Then, fill the pool with clean water and start treating it with chlorine tablets for a fresh start. It pours a lot of money into chemicals that don't have enough effect.

1 comment

Brandon True

This is a great guide! Thanks a bunch for writing this up – I really appreciate that it’s readable as well. I’ll be using this to help some of my clients in the future!

Leave a comment

Please note, comments need to be approved before they are published.