Chlorine tablets are a great way to keep your pool water clean and sanitized, but if it is the only method you use to sanitize your pool you could be doing more harm than good.
Chlorine tablets, also known as Trichlor, seem like a great and easy way to keep your pool water clean, but the cliché “ too much of a good thing” comes into play when you use only chlorine tablets. Chlorine tablets have some side effects pool owners may not know about:
- Chlorine tablets lower the total alkalinity of the pool and have a pH balance of 2.9
- Chlorine tablets also are 52% cyanuric acid( which is a conditioner or stabilizer) by the weight of the tablet and this increases the cyanuric acid level in the pool water.
In short chlorine tablets lower the pH and total alkalinity of the pool and raise the cyanuric acid levels. When you use chlorine tablets in moderation they work really well and are a great asset for keeping the pool clean. When chlorine tablets are the sole source of chlorine in a pool the water will become acidic over time. The CYA (cyanuric acid) level will get so high that it will become unmanageable and the one way to decrease the acid at this point is to drain the pool and refill it with fresh water to dilute.
Draining your pool may seem like it’s not a big deal just a bit of a hassle but it’s not a good thing for many reasons including:
- The pool might “float” due to hydrostatic pressure or surcharge conditions
- The shell may crack
- Checking or blister of the plaster can occur
- Pool light can blow up if turned on while pool is empty
In addition to the above issues of draining a pool it is not environmentally friendly to refill your pool more often than needed and you will probably see a rise in your water bill as well.
The ideal pH range for a gunite swimming pool is 7.4 to 7.6 and the ideal TA level is 80 to 120 ppm. The pH balance in a gunite pool naturally rises and the use of chlorine tablets help to lower the pH and is a great benefit if using chlorine tabs when used in moderation. If you use too many tablets you risk lowering the pH below 7.2 making the water acidic and it begins to affect the plaster in the pool, any pool equipment used in the pool and and the skin and eyes of anyone who swims in it. A huge problem happens when the TA level in the pool becomes low around 30ppm. This has a harsh effect on the plaster and will begin to soften and erode the plaster in the pool. One sure sign of eroding plaster is white sand in the Polaris bag showing the alkalinity of the pool water has been too low for years.
If you have been adding and adding more chlorine tablets and your water is still green this is because the tablets have raised the CYA level and it has gotten over 100 ppm which affects the ability of the chlorine to disinfect the water. The CYA is so high it prevents the chlorine from doing its job leaving murky and green water. The only way to fix it is by draining the water from the pool.
The best way to keep your pool water sanitized is to use a combination of chlorine tablets and liquid chlorine or sodium hypochlorite, more commonly known as bleach year round. The best time to use chlorine tablets is during the summer. Chlorine tablets have a time release of chemicals as the tablet dissolves in the water throughout the week keeping the water in check until your trusty pool cleaner can come for the weekly service and balance it with liquid bleach.
Chlorine tabs seem so much easier because they are smaller and easier to store and transport. Liquid bleach seams to be more of a hassle to use but it is better for the pool and keeps the water in balance much easier. Are chlorine tablets bad to use? No, they are not, but they should not be the only source of chlorine in your pool .
For the best expert pool care contact the crew at EverClear Pool Service. Image by Birdies100 Flickr