Free Chlorine at 7...

[dubele]

Hello,
Yesterday I shocked my pool because the combined chlorine was high. I just tested the levels with my Taylor k-2006 and it shows my free chlorine at 7. This is very high....is this normal?....and just a result of the shocking?
Thanks,
Doug

 

[jblizzle]

Is this normal? Well, depends where your FC was, how much chlorine you added, what your CYA level is, how much sun exposure you have and whether there is something in the water ... so I guess the answer is ... maybe?

We do not recommend what you are calling "shocking". We recommend you follow the SLAM Process.

BTW, 7ppm may not be "very high" in fact it could be too low if you CYA is high ... see the FC/CYA Chart.

 

[Richard320]

If you're worried about going swimming in it because it's too high, don't be. Even without any CYA, 7 is still below shock level. 7 could be too low, though. The pool's only two weeks old, correct? It would be prettty hard to drive CYA above 90 to where 7 is too low in so short a time, but I guess it's possible if someone has been pouring bags and buckets full of powdered chlorine in the pool indiscriminately.

What you think of as "shocking" is the pool store method of a single massive liner-fading dose of some powdered chlorine. How high did you drive the FC? What's the CYA level? What's the CC level now? What does the water look like? Is it cloudy, or crystal clear, or green and chunky? Are the walls slimy? To answer your questions correctly, we need more information. This article will explain it: http://www.troublefreepool.com/content/115-read-before-you-post

 

[Casey]

Can you please post a full set of test results please.

 

[dubele]

Thanks guys. Here are some answers to your questions:

The pool was first filled with water on 5/5....just over 3 weeks ago. Yesterday, before the shocking my test results were:

Free Chlorine: .25
Combined Chlorine: 1.1
pH: 7.8
Hardness: 236
Alkalinity: 105
Cyanuric Acid: 16
Copper: .1

My pool is going to be a salt pool. I have a chlorine puck in each of my two skimmers. There was swimming over Memorial Day, so maybe that is what cause the combined to go up. Looking at the water, it looks great....very clear. Don't know about the walls and if they are slimy....too cold to go in

Need any other info??

P.S. - I've said this before, eventually I will be following methods here.....but not until I get comfortable with traditional styles. I learned yesterday that I can get muriatic acid at Home Depot and will do so from now on....it's half the price as my builders retail store!! Also, they sold me an Alkalinity Increaser......sure looks like baking soda to me. I'm learning...just need time to get the basics. Thanks agian!

 

[jmbradwell]

As far as getting MA from Home depot, compare prices and strengths. In my area, the best price I've found for MA is at the pool store. Other than toys, that's the only thing I buy at the pool store.

 

[woodyp]

Why learn two..."styles". .......as you put it?

 

[steveg_nh]

I learned quickly that the traditional method is largely filled with errors and guesses. I quickly believed what I learned here and my pool is perfect and easy to care for.

Also at Home Depot I've only found the "safer" muriatic acid which doesn't seem to be the same stuff as you can get elsewhere and what you should be using in your pool.

 

[Isaac-1]

Those traditional massive "shock" doses of chlorine with low CYA level just shortens the life of your equipment in the name of "easier" meaning quick pool management.

Ike

 

[bridgman]

What did you shock with ? Just wanted to remind you that most shock powders will raise your CYA pretty quickly, and until you get an SWG (guessing that's what you meant by "salt pool" ?) you want CYA level in the 30-50 range.

One of the most important pages in Pool School is the table showing the relationship between CYA level and desired FC levels :

http://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock

What the table says for your case is basically :

- at 16 CYA shock level is a bit below 10, and since swimming up to shock level is generally considered safe your FC level of 7 should be fine
- at 16 CYA you want to target FC=3 and never let it drop below 2
- at 30 CYA (which is probably where you are now after shocking) you want to target FC=4 and never let it drop below 2
- at 50 CYA (which it could be at already depending on the amount of shock you added) the numbers are "target 6, never let drop below 4"
- etc...

Anyways, in general you're more likely to have problems from FC too low than from FC too high. For now you'll need to keep an eye on your CYA level and switch from pucks/shock to bleach pretty soon to avoid driving your CYA level too high. If you used liquid shock (usually slightly stronger bleach) then Carry On

 

[tim5055]

Multiple styles of pool care will just confuse the situation. Read Pool School a few times and get your own good test kit. You will need to,order the kit, the ones most pool stores sell just won't do the job right. The number you posted appear to have come from the pool store, and their testing (with a few exceptions) is poor - especially with the CYA.

 

[JesseWV]

Learning the TFPC method will also gain you an understanding of the "traditional" method and why it's not recommended. So don't worry, you won't be missing out on anything, other than wasting your money and pulling your hair out.