First Post - ZERO Chlorine

[donnah1301]

Okay - so I dug around --- found the POOL CALCULATOR (HOORAY) --- and believe that with everything else in balance (except for the TC) I'll be good with 100 oz or so of 6% bleach. Here are the numbers:

TH 300
FC 0
pH 7.5
TA 100
CYA 30-50

13500 gal AG

Location - outside of Kansas City (90+ tomorrow)

[aylad]

Hi, and welcome to the group!!

Your CYA reading leads me to believe that you're using test strips for your testing--if that's the case, don't get too excited until you confirm your readings with drop-based testing (check the test kit link in my sig for more info). However, if your CYA is actually 30-50 ppm, then make sure that you keep your chlorine between 3-6 ppm at all times. If you let it get below 3 ppm for too long you'll be fighting algae. In 13,500 gallons of water, each gallon of 6% bleach you add will increase your FC by 4.4 ppm, so your estimate of 100 oz is pretty close. Just add it, give it a little time to circulate, and test for it.

However...if your chlorine is currently at zero, and you are having 90 degree days, then I would go ahead and shock it to start off, because you probably already have some algae trying to get started. It doesn't take long...

[donnah1301]

Thanks so much for the help. I did get a decent test kit and am good to go. Thanks again!

[PoolDoc]

Just so you know: there is just one "decent test kit" that's widely available locally: the HTH 6-way kit, made by Taylor and sold by some Walmarts. It is fully compatible with the K-2006, and since the chlorine test is OTO, it continues to work when chlorine levels are above 5 ppm.

The Taylor K2005 is sometimes available locally, and is a good kit for everything EXCEPT testing chlorine. But, since it uses the DPD color match test, a zero chlorine reading can mean you have NO chlorine **OR** it can mean you have more than 10 ppm of chlorine. So, until you get a HTH 6-way OR a K-2006 DPD-FAS kit OR a K-2006 PLUS the Taylor 1515 DPD-FAS single function test . . . you do not have a good kit.

There are a very few other kits that have the DPD-FAS test, but they are not widely available.

[donnah1301]

I got the HTH 6-way.

[PoolDoc]

Ok. with TA=100 and CH=300, be careful if you are using cal hypo. If you add it directly to the pool, you are likely to make the pool very cloudy.

You probably want your pH at the lower end of the acceptable range.