Beware of Household Bleach!!


Bronze Supporter
Apr 16, 2019
Bremen, GA, 65 m west of Atlanta
Pool Size
Liquid Chlorine
We've been using Laura Lynn household bleach for the pool (no additives) from Ingles, the local supermarket chain, and last year it always tested out at 6%. This year we've had two jugs that tested out at 0 -- basically water with just enough chlorine to make it smell! We tested by adding enough to bring FC up to 7, then tested again after 30 min. No change in the FC. Tried with the 10% from Wal-Mart (Pool Essentials), and it brought the FC right up to 7.

I don't know if other household bleaches are doing the same, but I suggest checking each new gallon to make sure it's actually chlorine, and not water with a touch of smell.

Here's how to get the percent bleach using PoolMath:

1. Put your usual amount of bleach in the pool.
2. Test after 20-30 mins. If the FC is different from what you expected, go to step 3. If not, congratulations! Your bleach is fine!
3. Enter the FC in the Chlorine tab of PM.
4. Enter percentages in the strength box and hit the ✔ mark. Note what the amount to add is.
5. Keep changing the percent in increments of 1 until the amt you added matches what PM suggests.
6. That's the actual percent sodium hypochlorite in your bleach.
7. Adjust the amt you add accordingly.

I did this with every new jug of LL household bleach, and it was consistently 6% last year. This year is a different story.