enzymes, metals, and shocking


In The Industry
Mar 29, 2007
Knippa, Texas
I've learned that high levels of chlorine will destroy enzymes (such as Pool Perfect) and wondered if a non-chlorine shock would leave the enzymes undamaged. I'm thinking that a strong oxidizer would probably take out the enzymes, but I wanted to get a definite answer.

Also have heard that shocking with chlorine will inactivate a chelating/sequestering agent and cause metals to fall out of solution. Would using a non-chlorine shock prevent that problem? This came up in another thread but there were other issues being addressed and I guess it got buried.


chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
San Rafael, CA USA
I cannot say definitively, but to the extent that the enzymes get destroyed through a process of oxidation, then the non-chlorine shock may be as destructive as super-chlorinating. However, you need to ask yourself why you shock your pool in the first place. For an outdoor pool exposed to sunlight, you rarely need to shock the pool and rarely find Combined Chlorine (CC) levels persisting more than a day.

WHOOPS! I just read that you have an INDOOR pool. Sorry, my mistake. In that case it is often best to use a non-chlorine shock anyway because it is more effective against the formation of CC since there is no sunlight to help break them down. I would use non-chlorine shock regularly (weekly) in an indoor pool. This will also help cut down disinfection by-product production. You should also consider using a small amount of CYA (10-20 ppm) since that will help prevent corrosion as well as slow down disinfection by-product production (just in case the non-chlorine shock misses anything).