How To Read A Water Care Test Strip

Have you ever looked at the testing strips you use test the water of your hot tub or pool?  Does it make sense to you?  If so, congratulations, but to many this is just a weird color coded and set of number; basically information that does not translate to an action to be taken.  Here we try to decode the water code and why. 

FCL free chlorine. This is the sanitizer level of the pool. For pools, the safe level is 1ppm-3ppm; for spas 3ppm-5ppm.  You should test this weekly and add chlorine as needed to keep water clean, clear and free of algae.

Tips:

• When adding wear gloves or old clothes. Most people almost always seem to bleach themselves.
• When opening tab buckets always turn your head, gases can take your breath away, in severe cases if they get wet (don’t leave out near the filter system) you can burn your lungs.
• If  adding liquid shock to the pool I suggest resting the container on the top step of the pool and dumping in. This is to avoid splashing on the deck and causing bleaching of the deck.
• If adding granular chlorine shock. Always premix.
• Usually needs to be regulated weekly

Rule of thumb:

• DO NOT put pool chlorine into your spa or spa chlorine into your pool. 
• For pools use one tablet (that is the hockey puck shaped thing) per 10,000 gallons of water.  For the average pool that is 3 – 4 tablets per week depending on the weather and use of the pool.
• For chlorinated spas, use ½ oz of chlorinating granules per 500 gallons of water.

ALK alkalinity. This is the buffer for the pH in the water. The pH level in pool water can directly affect the efficiency of the sanitizer (chlorine). The pH level for the human body and eyes range from 7.2 - 7.6; this is the comfort zone. If the pH of the water is too low or too high it can irritate your eyes and skin. Often, when people complain of eye and skin irritation they think it is the chorine levels that is causing it, but no, its the pH level. When the pH of the water is not in balance it can also do damage to the pool’s equipment and surface.

Tips: 

• There is one chemical that helps you raise the alkalinity level and one that helps you lower it. 
• Either chemical should be pre-mixed as per the directions on the container and added to the pool. Wait a couple of hours and test the water again to see if you got it right.
• Usually regulated weekly or after a storm.  Note: The pH of rain is very low and will change the pool’s alkalinity level

CH calcium hardness. All water needs calcium to be in balance, if not it becomes “aggressive” and will take it from the pool surface. This is why a gunite pool with poor calcium levels will feel very rough to the touch; the water has pulled the calcium from the walls. In a vinyl lined pool the liner becomes discolored as if bleached and becomes very brittle and more susceptible to tears even from a toe nail. (YUCK!) Balancing the calcium level of the water is usually only needed in the spring when opening the pool, and most often stays in balance for the summer season. Check monthly to be sure and add the appropriate calcium hardness product for your spa or pool. Keeping calcium in balance can extend the life of a marble dust finish or liner of a pool or shell of the spa. 

If you are managing the water quality of your pool and spa by yourself, please remember not to use pool products in your spa and spa products in your pool.  Your local pool and spa water care product supplier (the pool store in your town) will be able to tell you want to buy and what you need.  Follow the instructions on the container for proper amounts to use and how to use it.

Tips for using Test Strips:

• Submerge the strip 6" under water for two (2) seconds, and remove with the pads facing up.
• Shake ONCE to remove excess water.
• Place test strip up to the color legend and read immediately in this order: FCl > Alk > pH > CH
• Add the appropriate chemicals indicated.
• For Pools and Spas with a lot of use, check twice per week.

How to determine the amount of water in your pool:

• Rectangular:  Length x Width x Average Depth x 7.5
• Round: Diameter x Diameter x Average Depth x 5.9
• Oval: Length x Width x Average Depth x 6.7

How to determine the amount of water in your spa:

• Rectangular:  Average Depth x  Average Width x 7.5
• Round: Diameter x Diameter x Average Depth x 5.9
• Oval: Length x Width x Average Depth x 6.7

Prefer the high tech, iPhone App method? Here is a great one we found.

 IPoolTester is an all in one program to assist you in managing your swimming pool, hot tub, waterfall or any other body of water, which requires periodic testing, balancing and maintenance.  Using commercially available test strips in combination with the iPhone, iPoolTester can quickly report the current water conditions as well as calculate which chemicals are necessary to balance the water.  Testing your pool is made as simple as (1) dip the strip into the water (2) take a picture of the strip (3) read the results and dosing suggests from iPoolTester.  

Looking for a Pool Calculator, yup a Pool Calculator, we found this one.  Plug in the numbers and it will give you the size of your pool, how much chemicals to use based on your test strip results and more. 

While these are great tools for the DIY pool person in your house hold, it does not replace the experience and expertise of a professional.  If you are unsure of what to do, go to your local pool store with a sample of your pool or spa water and ask for help.  Or better yet, schedule service and get on the right track for enjoying your pool and spa this summer season and beyond. Sometimes it is just worth it to pay an expert.

Need Chemicals and Test Strips?  We sell them in showrooms or in our Online Store.