If your chemistry readings determine a water issue, or you notice something is off with the water, it might be time to shock your pool. This essentially means adding a lot of chlorine to increase free chlorine (FC) levels over a period of time.
But, how much is a lot? Use our pool shock calculator to understand just how much chlorine is needed to reach the FC level needed to shock your pool.
Using the Pool Shock Calculator
The calculator determines your shock level based on your current chemistry levels.
FC levels should always be determined by how much CYA is in the water. Typically, FC should be 7.5% of your CYA level. When shocking the pool, that number increases to 40% of CYA.
While the calculator is pretty straightforward, there are a couple of items that are needed:
- Your pool volume in gallons. This important item helps determine how much chlorine you need to reach your shock level.
- There are different types of chlorine that you can use. For liquid chlorine and calcium hypochlorite (cal-hypo), you’ll need to input the strength as well since there are various strengths you can buy.
- Your current CYA and FC levels.
Know The Pool’s Volume
It’s nearly impossible to calculate chemical dosages without knowing how much water is in the pool. A 25,000-gallon pool will need more chlorine than a 7,500-gallon pool.
If you don’t know the volume offhand, we can get a pretty good estimate using a pool volume calculator.
The Best Chlorine to Shock a Pool
For shocking, it’s highly recommended to use chlorine that works fast. For this reason, we recommend using either liquid chlorine or cal-hypo.
Trichlor and dichlor are too slow and too much of them at a high volume will significantly increase your CYA.
Test To Determine Your FC and CYA Levels
We only want to shock once, so having accurate chemistry levels will help us determine how much chlorine is needed.
Use an accurate testing kit to get the best results.
The most accurate and reliable pool testing kit.
Type of Chlorine Test: FAS-DPD
Read our full Taylor K-2006 Review.
Get Ready to Shock!
Knowing how much chlorine is just one step in the shocking process.
Hopefully, this is a one-time thing and you can go back to enjoying the pool instead of fighting it!