Hazy water

[Dan Heinrikson]

If my total chlorine (TC) is 8.5 and my Free Chlorine (FC) is 7.5, do I have to shock my pool until they are equal?
Everything else is in the normal range but pool water is a bit cloudy. I can see the bottom but water is not crystal clear; it's hazy.

[Watermom]

Hi, Dan, and welcome to the Pool Forum! Yes, you need to shock the pool but how high you need to shock depends on your CYA level. (See the Best Guess Chlorine Chart in my signature below.)

Can you post a complete set of current water testing results taken with a drops-based kit for us to look at? Also, tell us exactly what all you have put in the pool, meaning ingredients and not just 'shock.' Then, somebody here can better advise you.

Also, create a signature line (directions in link in my sig) and in it, tell us what type of pool, the volume, type and size of filter and size of pump.

[PoolDoc]

Dan sent by email:

Not sure that I understand what the chart is trying to convey. My CYA is 30-50 according to test strips. What is the difference between shock and +shock+? How do I create a signature line? Why don't I have permission to update my profile now that I am registered.
I replied to your link but am not sure you received it.

The percent of chlorine that is active, and the amount that is in 'hidden reserve" is determined by your CYA level. When your pool is in 'trouble', you need a larger 'active' chlorine level: that is the "shock" level. When your pool is in REAL trouble (resistant algae, etc) you need an even higher level, ie, "+shock+".

Regarding registration: I have a convoluted process that has succeeded in keeping spammers out. As it happens, I've largely solved that problem through OTHER means, and had intended to relax the registration requirements. But, for better and worse, traffic on PoolForum has increased dramatically. I'm not sure why, but the result has been that more people have made it through the gauntlet, then we've been able to keep up with. Were I to relax the registration process now, the quality of responses would decline.

Not everyone here agrees, but in the end, it's my forum, and I've decided I'd rather have people just lurking, but reading GOOD responses, than to have more people registered, and then either get poor response, or no response at all.

[Dan Heinrikson]

OK, here we go. I have a 24' round, above ground pool with a 52" wall, so 15,000 gallons on the high side.
The filter is a "Hayward" Voyager Swimpro manufactured for "POOL O RAMA". The filter media is a pleated, paper, 100 sq. ft. cartidge. I am also using an inline "Nature 2" sanitization filter with asscocated cartridge. At this time my pool is clear; looks good in fact. The issue now is that Free and Total Chlorine do not match. Here is the chemistry:

CYA = 90
TC = 9.0
FC = 7.6
pH = 7.7
TA = 150*
Phosphates = 1000

* Adj TA = 123

[Watermom]

You are over-estimating your volume. It is more like 13,500 gallons. (Manufacturers always tell you it is more than it is because that appeals to people. The number they give is usually if the pool is 'running-over full.)

I'm assuming these testing numbers came from a pool store? You need to be able to test your own water. We recommend a Taylor K-2006 or 2006 which you can get from the test kit page in my signature below.

Don't worry about the phosphates. That is mostly just a way to get people to buy another product that they don't need -- a phosphate remover.

If your chlorine testing numbers are indeed correct, that means that you have a CC reading of 1.4 which is not good. To get rid of it, you need to maintain the chlorine at shock level which is based on your CYA level. (Please read the Best Guess Chlorine Chart in my signature.)

How does the water look, by the way? Still hazy? Is it green?

Your CYA is pretty high so you should not use any more stabilized chlorine meaning no trichlor pucks or dichlor shock powder. Just stick with plain, unscented household bleach. Generic is fine and is what most of use. In your pool, each quart of 6% bleach will add 1ppm of chlorine. A gallon will add 4ppm. Use that as a reference to help you figure out needed doses.

Get rid of the Nature 2. It adds metals to the water which causes a whole other set of problems. (One of the metals it adds is copper which is what causes blonde hair to turn green and stains pools.) We do not recommend the use of those units.

*IF* you have been using the Nature 2 unit for awhile, you might want to have a pool store test your water for metals before you shock it. Shocking a pool with metals can cause the metal to drop out of suspension and cause stains. If you do have metal in there, you'll need to use a metal sequestering product. We'll wait to see if it is needed before discussing that, though.

Hope this helps.

[Dan Heinrikson]

Hi,

My pool is very clear. The only problem now is the 1.4 CC issue. To be certain that I understand, are you telling me to add regular Clorox Bleach to the pool? I thought that non-pool bleach/Chlorine was toxic! Also, am I suppose to add enough bleach to raise my FC from 7.6 to 20, or from 7.6 to 75? (CYA = 90) AND, how long do I sustain those levels?

Dan

[CarlD]

All chlorine is toxic if used incorrectly. Pool store "Liquid Shock" is either Ultra Bleach (6%) or double strength (12%). Same stuff. Be sure to use regular or ultra unscented, non-sudsing, non-gel, ordinary bleach. Generic/store brand is fine. Both the pool store and the bleach companies sell a solution of sodium hypchlorite and brine (salt water). Used as directed, it's as safe as any other chlorination...safer, too, than some.

[aylad]

Hi,

My pool is very clear. The only problem now is the 1.4 CC issue. To be certain that I understand, are you telling me to add regular Clorox Bleach to the pool? I thought that non-pool bleach/Chlorine was toxic! Also, am I suppose to add enough bleach to raise my FC from 7.6 to 20, or from 7.6 to 75? (CYA = 90) AND, how long do I sustain those levels?

Dan

Yes, we're advising you to add enough bleach to raise your FC from whatever it is now to 20 ppm. In 13,500 gallons of water, each gallon of 6% bleach you add will raise your FC by approximately 4.4 ppm, so you can use that as a guide to figure out how much you need to add. You need to reach that level, and then hold it there as consistently as possible, which will mean testing and adding more bleach as often as you can during the day, until you are losing less than 1 ppm of chlorine when testing at night and again in the morning before the sun hits the pool (to rule out UV consumption) and until your CC gets to 0.5 or less.

Once you've reached that point, you can let your FC drift back down, but with a CYA of 90, you'll need to always keep it in the 8-12 ppm range to keep the algae away.


I use WalMart's generic ultra bleach in my pool--it is 6% the cheapest I can find it around here anywhere...

[PoolDoc]

I thought that non-pool bleach/Chlorine was toxic!

Pool stores tend to express the idea that ANY pool chemical that's much cheaper than the version they sell, is "toxic" . . . or "damaging" or "useless" or whatever.

The best one I recall was that Clorox -- which comes in a plastic bottle -- will dissolve plastic pipes! (Granted, the bottle is PE, and the pipes are usually PVC, but it's unlikely the pool store dude knew that . . . and if he did, he'd have known that PVC is fine with concentrated bleach!)