Pool Water Test Strips vs. DPD Test Kits vs. Digital Water Labs: Which is Best?

Have you ever walked out into your backyard on a hot summer day, eager to have a relaxing swim in your pool, only to discover that the pool has somehow turned green? Ah, pools… nothing brings us both warmth and comfort as well as anger and disgust quite like a pool. Maintaining safe and crystal-clear water should be the number one priority of all pool owners. The truth is that green water happens often and can be easily prevented with the right tools. 

There are three primary tools we in the pool industry use to test pool water chemistry to ensure clear, and more importantly, balanced pool water: test strips, DPD test kits, and digital water labs. Achieving water balance means maintaining chlorine, pH, alkalinity, calcium hardness, and cyanuric acid levels at the ideal pool water levels. Maintaining balance without testing your water regularly is a fool’s errand, and you will end up spending much more on chemicals than you would if you were using some sort of test. Let’s take a look at these three testing methods in depth.

Test Strips: Quick and Convenient Testing

Pool water test strips are easy to use, and fairly accurate, though not as accurate as the other two options. Test strips are typically bought because of the lower cost and simplicity of reading the chemical levels. Typically they come in a small bottle, about 100 strips per bottle. Printed on the side of each bottle is a chart showing the ideal colors (levels) that each chemical should be at. You dip the test strip fully into the water and quickly pull it out. The test strip will have multiple little squares on it that will begin to change colors. At about 15 seconds, you should have the correct levels (always refer to the bottle – different test strips may take more or less time to display the correct levels). Compare the levels on the strip to the ideal levels on the bottle, and you’ll know where your chemicals are sitting. Unfortunately, after this point, it is up to you to determine which chemicals and how much needs to be put into the pool to achieve balance. Another downside is that the state of your water can affect the test strip’s ability to read the chemical levels, thus it is not 100% accurate all the time. 

DPD Test Kits: Precision in a Package

Accuracy is key when testing pool water. Adding in too much or too little of a chemical can create more problems than solve in some cases. DPD (N, N-diethyl-p-phenylenediamine) test kits are a step up in terms of accuracy. These test kits are popular among seasoned pool owners who do a lot of chemical adjusting and are always on top of their water balance. They use reagents that react with pool water, changing the water color to match the parameters on the test kit. We recommend a 4-in-1 test kit that measures chlorine, combined (dead) chlorine, pH, and alkalinity. With these test kits, you will use a bottle to take a water sample. When taking the sample, cover the lid with your thumb upon submersion to avoid any surface debris from getting into the bottle. Go about elbow-deep into the pool to get a more accurate sample. When you have your sample, you will pour it into a glass display box, and then add the corresponding reagent to the water. When the color is changed, you will compare it to the ideal color ranges in the kit, and you will have your chemical levels. Similar to the test strips, this is where the magic stops. You will then have to determine what chemicals, and how much to add. 

Digital Water Labs: Digitalized Pinpoint Accuracy

Digital water testing is the pinnacle of testing pool water. They are the most thorough and accurate, and even give you the exact amount of chemicals that are required to achieve balance. Digital water labs are very expensive and typically only used by pool professionals in pool stores. You bring a water sample to your local pool store, they will take a small sample from the water, insert it into a spindisk, place the disk in the testing machine, then run the test. After about 30 seconds, the test will spit out your results. This will include a detailed list of all the pool chemicals including free, total, combined chlorine, ph, alkalinity, calcium hardness, cyanuric acid, bromine etc. These awesome little machines save you the hassle of having to determine how much chemicals you will need.

Choosing the Right Method:

The choice between pool water test strips, DPD test kits, and digital water labs depends on several factors, including your pool management goals, budget, and comfort level with technology.

• For Casual Users: If you are a casual pool owner looking for a quick and easy way to check basic water parameters, pool water test strips may be sufficient.
• For Precision Seekers: If you require more accurate readings and are willing to invest a bit more time in testing, DPD test kits offer a good balance between accuracy and ease of use.
• For Tech Enthusiasts: If you value cutting-edge technology, data tracking, and the highest level of accuracy, a digital water lab may be the ideal choice. 

Conclusion

So there you have it, the three water testing solutions. You can’t really go wrong with any of these if you are experienced with pool chemicals and maintenance. The choice comes down to how accurate you want to be with your pool balance. Are you someone who likes to maintain balance 24/7? If you are, you might want to stop in a pool store once or twice a week for a professional test, or you can buy one for yourself, just know they are very pricey. Seasoned pool owners can get away with the DPD kits and can probably determine how much chemicals they need at a certain time. The only way to reach this point is to stay on top of your pool chemistry and test the water at all times. 

More videos/articles to explore:

How to Test Your Pool Water: Digital Water Labs, DPD Test Kits or Pool Test Strips?

pH and Its Harsh Effects On a Pool

Inground Swimming Pool Water Testing: How to test your water with Test Strips

 

Written by Logan Edgemon