When to shock a pool


New member
Jul 21, 2007
I had a question regarding when to shock a pool. My understanding, which is cobbled together from information I found online, is that shocking is supposed to oxidize the combined chlorine and free it up. I also read that you should shock your pool every 1-2 weeks. I've been carefully measuring my pool and so far I have not seen any combined chlorine, so I have not been shocking my pool. Should I shock my pool even if there is no combined chlorine? Sorry for the newb question.

Also for those of you who think I'm an industrial spy (http://www.troublefreepool.com/viewtopi ... 4715#14715) bent on the fall of chemical based pools, I'm sorry to disappoint, but I'm just new to pools and trying to figure out what works best and what doesn't.

Thanks for any responses.



Well-known member
May 25, 2007
During the season, I shock ONLY when I test CC above .5 ppm.

I shocked when I opened, once mid year (and I didn't need to then, I test my water that had been sitting un-circulated in full day sun) and unless something changes will only shock when I close.


LifeTime Supporter
May 27, 2007
Spring Hill, Florida
I'm with Rangeball. I shock when CC exceeds 0.5 ppm. I've not shocked yet this year (knock on wood).

I have a SWCG which is set to maintain FC at 2.0 ppm, and I keep the borate level at 50 ppm.


Well-known member
Jul 3, 2007
Thanks for posting that question, I was wondering the same myself since I haven't had CC since initial open/shock. If I may ask another newbie question here, what are borates and how do I test? I have the TFP test kit and don't see a borate test included?


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
Borates are the primary ingredient in borax. Borates have several properties that are useful with pools. They raise PH, buffer PH, prevent algae, reduce chlorine usage, improve water feel, and add sparkle. If you are only using borax to raise PH you probably don't have enough in the pool to detect any of the other properties. For the full effect you need to have borates at 30-50 ppm. Pets that reguarly drink a lot of water from a pool with 30-50 borates might have problems. Pets should be trained not to drink from the pool. There is no risk to people or kids.

Test strips are the most pratical test method. LaMotte Borate test strips seem to be the best but are sometimes difficult to find. AquaChek Borate test strips are acceptable. Some pool stores can test for borates.