"Shocking" the pool as an alternative?


Active member
Dec 30, 2015
San Jose, CA
I clean my pool on every Sat by myself (brushing, skimmer, testing and adding chemical etc), and I have to be out of town in early July for two weeks (considering of the temp in San Jose, CA at that time). Let's just say that I couldn't find a good local pool guy to come to my house during my absence. I definitely don't want a GREEN pool when I come back, but wonder if I could raise the FC to a shock level, and let the pool consume the FC by itself in the next 14 days. Is this possible or practical?

I tried it before that maintaining a regular FC level and leaving the pool there for a week in summer is fine, I have the solar cover and under water robot, and run pump/filter 4hrs day. But things will go bad quickly after 7/8 days, so this time, I like to give some "FC buffer".

  • E.g., Based on the CYA right now, I raise the FC to 25+, then two weeks later, I assume FC may drop to ~4-5, which might be still OK to prevent algae growing. Then I just come back and take it over.

The latest water test:
FC: 6
CC: ~0
PH: 7.4
TA: 30
Hardness: 20
CYA: 45

Thank you very much for your thoughts!




TFP Expert
LifeTime Supporter
Jan 6, 2010
San Dimas, CA (LA County)
The problem is that chlorine loss due to sunlight is a percentage, not a fixed 2 or 3 ppm per day.
Check this graph I lifted from Pool Water Chemistry
You'll see it stops at 10 ppm. But you can clearly see that as the concentration increase, the loss slope gets steeper. Jacking FC to 25 will leave you at 12 or less after the first day. No way you'll last two weeks.

Solution: make sure your pool is absolutely perfect before you leave. Add polyquat 60 algaecide a few days before. buy or beg a few trichlor pucks and buy a cheap floater and leave it in the pool.