Chlorine is GONE

[CarlD]

If you want to get an estimate of how much chlorine it might take, do a bucket test by

1) taking a 2-gallon bucket of pool water and
2) add 6% bleach to it noting that every 1/4 teaspoon of 6% bleach in 2 gallons is 10 ppm FC.
3) Add some bleach,
4) wait an hour,
5) measure the FC.

If it's not holding (i.e. much less than 10 ppm FC)

6) then add more,
7) wait an hour,
8) remeasure.
9) Once the FC holds then that cumulative amount of FC is what will be needed for your pool -- it could be a lot.

Richard

Richard, this is a seriously cool test and I think we should consider adding it to our stock of tools.

Thanks!

Notice I broke it up into exact steps to follow.

[chem geek]

That's great. Steps 2 and 3 are the same (i.e. adding some bleach) so step 3 can be removed. Other than that, it's a very clear procedure. Thanks for cleaning it up.

Though it would be nice to be able to predict the amount of chlorine needed solely from an ammonia test and Combined Chlorine (CC) test, it often takes more chlorine than predicted since there may be some partially broken down CYA that doesn't show up either as CYA nor as ammonia and there can also be some dead algea or bacteria that don't show up as CC.

I describe technically how bacteria degrade CYA to ammonia in this post and I describe my personal experience with this effect in this thread.

[clueless at times]

"I would not trust the pool store numbers, especially not for CYA. "

Well that turned out to be accurate. I had the water retested and CYA is 180. I think that explains a lot of my problems.

Thanks to you all for the advice.

[Watermom]

You know how to handle it at this point? If not, give a shout and we'll help. Good luck.

[clueless at times]

I drained the pool completely, washed it down with bleach to kill the algae and brushed the heck out of it. It is being filled as I type. Question, should I wait until it is completely filled to add bleach or dump some in as it fills? Obviously this will take about 20 hours to fill, do I wait until the pump is up and running before adding anything?

[Watermom]

You can add a little bleach as it is filling if you want. Find something to stir it around with so it isn't a real high concentration sitting in one place. ( a clean broom, an oar, etc.) Or, if you think it won't be longer than 20 hours or so, you can just wait until it is full and the pump is running. 20 hours isn't so long.

[clueless at times]

ok. I think it took about 20 hours last time I filled it three years ago. Thanks so much for the advice.