Chlorine - how high is too high?
Last time we reviewed why it’s important for those with salt chlorination systems to adjust their chlorine output with the seasons. As discussed, heat allows algae to bloom more rapidly, so a higher chlorine level is required to keep your pool water optimally sanitized.
But what happens if you crank-up your production too high?
And what does that mean for the safety of you and your family?
To be considered safe for swimming, your chlorine level should fall between 1.0 and 3.0 ppm (parts per million), ideally right around 3.0 ppm. Any reading lower than 3.0 ppm, while technically inside the “okay zone” on most test kits, won’t keep your water truly sterile.
At times, when shock is added, your chlorine level may fall somewhere around 5.0 ppm, which is above the ideal range. If you’re swimming with this high a level you may begin to feel irritation on your skin or in your eyes. It’s also possible for your hair to be impacted as well. When your chlorination level gets to 10.0 ppm, no one should use the pool due to safety concerns. A level this high can even exacerbate asthma symptoms. Before you can dive back in you will need to reduce your chlorine level, some common methods of doing which being:
1) diluting your pool with fresh water
2) allowing the sun to naturally reduce your chlorination levels
3) adding chemicals (like Thio-Trine) to bring your chlorine level to a safe swimming level
Once your Chlorine level falls to 3.0 ppm or below, you’re good to jump back in!
Considerations for those with saltwater pools:
1) If you have an automatic cover and a salt chlorination system, you need to ensure your chlorination output is adjusted appropriately. One of the ways chlorine “exits” your pool is via evaporation. If your auto-cover is fully closed, there is nowhere for any evaporated chlorine to escape, which causes concentrated levels of chlorine in your pool. I have personally seen a covered pool with a salt chlorination system (set for typical/un-covered parameters) bleach hair and cause rashes in children, all because evaporating chlorine didn’t have a place to “escape” and stayed in the pool.
2) It’s also possible to over chlorinate your pool without an auto-cover.At times, you may notice algae growing in your pool. You have read up on your salt system and go to the panel to increase your chlorine production. If you put it up too high, your system will make more than enough chlorine to kill the algae and also some “extra.” This extra is the portion that would over-chlorinate your pool. Be sure to always monitor your output!
Other considerations:
1) Stabilizer (Cyanuric Acid) is a chemical that helps prevent chlorine loss due to sunlight. Cyanuric Acid “binds” your free chlorine, making it able to withstand the sun's ultraviolet rays without breaking down. Without a proper level of stabilizer (30-50 ppm) your chlorine will evaporate/break down significantly faster than a pool with an optimally balanced Cyanuric Acid level.
2) If you’re using your pool heater, you’re making it easier for algae and bacteria to grow. This is not meant to scare you - of course, we want our pools warm! However, the warmer your water, the easier it is for algae to bloom and take over your pool. If you’re running your heater often, be sure to check/monitor your chlorine levels frequently to ensure adequate sanitization.
3) High Chlorine can lower the pH of your water. This makes your water more acidic, which in turn increases wear on your mechanical parts (like your heater, pump, and filter), along with non-mechanicals (like O-Rings, and vinyl liners).
Hopefully this information has broadened your understanding of the impacts of high chlorination. The good news is that a weekly service from Harrison Water and Stone LLC can help to mitigate any risk - we always check your chemical levels and adjust them as needed. Feel free to reach out with questions!Until next time… keep on swimming!