Fast Chlorine Dissipation

[rqbanerjee]

Hi,
I'm in the process of opening a 25,000 gallon IG Vinyl pool. For the past few days, the chlorine has been dissipating at a SICK level.

The first thing I should tell you is that the pool hasn't been opened in 3 years or so. The water is cloudy and dirty, and i've been working on it for the past 4 days (friday - monday).

So, the pH is low but not too bad. It is around 6.8, and i adjust it daily with Pool store PH+ and baking soda. The alkalinity is on the low side, around 40ppm. I just added 8 lbs of baking soda and am waiting for the results. The stabilizer is suprisingly OK - 30-50 lbs.

I'm surprised that the chlorine dissipates so fast. I shocked last night with 2lbs of Calcium Hypochlorite, and at 5pm today the test strips shows 0.5ppm of free chlorine. Is this normal?

From the "STICKY" post, i read that the chlorine is probably destroying all the old Urea and Ammonia in the water, and that I should keep adding bleach to keey CYA(stabilizer) from getting too high.

Am i on the right track?


I'm about to post some pics so you guys can see what a disaster my pool was when I started. Cheers.

[duraleigh]

You are on the right track but you didn't shock your pool. To get to shock value, you needed 5 lbs of Cal Hypo...not 2. You should raise your Cl level to 15ppm and HOLD IT THERE until your pool water clears.

You will have very little luck testing accurately with test strips. That's a common, troublesome issue throughout this forum, year after year. A good test kit will save you a ton of money. Likewise, use borax instead of pH up will save you some bucks...it's the same thing.

The chlorine will continually be consumed in your pool. Fast at first because of all the impurities and then slower as your pool clears and it has less work to do.

[JohnT]

I'm surprised that the chlorine dissipates so fast. I shocked last night with 2lbs of Calcium Hypochlorite, and at 5pm today the test strips shows 0.5ppm of free chlorine. Is this normal?

Even if you had shocked at full strength, it still would have been consumed by the next evening. Cleaning up a pool uses a lot of chlorine. If you can find sodium hypochlorite/liquid shock/pool bleach at a pool store for a reasonable price, that will be your easiest chlorine source. Failing that, plain old unscented laundry bleach will work fine, you'll just have a bunch of empty jugs to get rid of. You need to get a better test method and start checking and adding chlorine as required at least twice a day, better 3 or 4 times a day to speed the process along.

[rqbanerjee]

Alright, Thanks! It is clearing up, just not that fast. The chlorine dissipates at a much slower rate now. I've also got the alkalinity and stabilizer at the proper levels.

I'll just keep shocking the hell out of it. Thanks!