Calcium Hardness levels?

Amy Adkins

Active member
Jun 8, 2019
When to shock is easy: never. Keep the chlorine high enough consistently and you never get algae.

Most of us raise the FC before and after a big swim party, but nothing like the overdone megadose the pool store recommends as a "shock."

With the exception of chlorine gas (which only gigantic commercial pools can justify) all forms of chlorine leave something behind. They all have a carrier of some type. Trichlor and dichlor leave behind cyanuric acid - CYA - while Cal-hypo leaves Calcium. Bleach/pool chlorine/liquid shock/whatever they call it is sodium hypochlorite and only leaves behind salt.

All this chemistry talk will make sense once you get some hands-on experience testing and dosing and seeing the results.
So I'm thinking if my CYA levels are already high, using regular bleach would be best..correct?


TFP Expert
LifeTime Supporter
Jan 6, 2010
San Dimas, CA (LA County)
Just not for sure whether using regular bleach is best or if using the higher strengths would be best? May cost more, but I'm sure if they work better, then maintenance may be easier.
Poolmath will calculate the dose based on the strength of the bleach. They're all the same chemical, except the fancier laundry bleaches add scents and additives you don't want. But it matters not whether you add 10 gallons of 6%, 6 gallons of 10%, or 5 gallons of 12%, you get the same amount of active ingredient.
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