hello everyone my first post and question?

[kingcoota]

My son's birthday is this weekend I've read all the articles on the site and learned alot thanks to everyones helpful info.

my pool is an inground gunite 20,000 gallon pool in St bernard louisiana (no oil in it yet jj)

my ph is 7.3
my T/a is 100
my cya is 30 - 40
my calcium hardness is 290

i'm going to shock my pool friday, two days before the party just wondering if you guys think two gallons of regular bleach will be enough.

[Watermom]

Welcome to the forum! You might want to wait until AFTER the party to shock. That is when there is more likely to be YUCK in the pool.

In a pool your size, a gallon of bleach will raise your chlorine by 3ppm. (Remember, usually bleach is not sold in gallon jugs anymore. Typically the jugs are only 3 quarts instead of 4 which is a gallon.) Shock level for your cya level would be around 15.

Have a great party!

[CarlD]

So that's 5 gallons of ultra bleach (that's what Watermom meant by 1 gallon raising FC by 3ppm--that's Ultra bleach. One gallon of regular bleach will only raise it by 2.5ppm--so you'd need 6 gallons of that.)

[kingcoota]

thanks for the help

[aylad]

Hi, and welcome to the forum!!

I'm up near Shreveport, but my hubby and I spend a good deal of time in your neck of the woods. Any oil around y'all yet?

Janet

[chem geek]

If you use Clorox Regular unscented bleach, then that is generally now 6% bleach while off-brand Ultra bleach is 6%. On the Clorox Regular, it says "6% Sodium hypochlorite" and also says "5.7% Available chlorine" and is what you want. I'm not sure if the off-brand Ultra bleaches label their chlorine content.

In Canada, Clorox has an Ultra bleach which is 6% while their Regular is 5.25%. Generally, you want the highest concentration bleach you can find as that's less weight to carry, though you can compare prices as I describe below. Also, Clorox bleaches have the lowest amount of "excess lye" in them so have a smaller effect on pH long-term compared to most off-brand bleaches.

If you have a local pool store or hardware or big-box store that carries chlorinating liquid, then that could be 10% or 12.5% or something like that and is another option for you. It's the same as bleach -- just more concentrated so is less weight to carry. You can roughly compare prices by computing the % per $ cost for the same quantity, so if 6% bleach cost $1.25 for 3/4 gallon, then that's $1.25/6/0.75 = 0.28 cents per % per gallon while if 10% chlorinating liquid cost $2.50 per gallon, then that's $2.50/10 = 0.25 cents per % per gallon so would be a slightly better deal.

Richard

[kingcoota]

no oil yet in the marsh, but should be in anyday now.