Where in the world is my chlorine going?
Updated: May 19
If you’ve just shocked your pool or just added chlorine and it’s gone already, you may have a chlorine demand issue. Some pool service companies will tell you that you have chlorine lock, which is also characterized by a strong odor of chlorine and too much cyanuric acid. The fact is, chlorine lock is a myth!
While there is such a thing as too much cyanuric acid, most chlorine demand issues are because of an over abundance of contaminants like dirt, algae, and other bodily excretia and lotions. And that chlorine smell is caused by chloramines - chlorine molecules combined with contaminants. Of course, you should hire a professional pool service to chemically test your water and determine the best course of action to take to solve your chlorine demand issue. If you do have too much cyanuric acid, you’ll need to drain some of your pool water and replace it with fresh water. As a general rule of thumb, you want to keep your chlorine level at about 7% of your cyanuric acid level. So if your cyanuric acid is at 50 parts per million, your chlorine level should be around 3 parts per million. But again, cyanuric acid is not the cause of chlorine demand. If your root cause is too many contaminants, the best solution is to super chlorinate your water by giving it a triple dose of pool shock.