Looking for pool shocking information from Ben Powell.

[aylad]

Your CYA got as high as it is from the use of stabilized chlorine like trichlor--with trichlor, for ever 10 ppm of chlorine it adds, it also adds about 6 ppm of CYA, so over a 2 year period it can get quite high.The only way to lower it is through water waste (splashout, frequent filter backwashes, partial drains, etc). It will come down, eventually, if you do not use any more stabilized chlorine, but it will be very, very, very slowly. You can do several partial drain/refills to help it along without hurting your liner too much, but if you completely drain the pool, the liner will float and will not be able to be refilled, in most cases, which is why Pooldoc stated that #1 above wouldn't be recommended. However, you could drain some of the water--a foot or two at a time, and refill that, and shouldn't hurt anything.

For more information on 3 and 4, take a look at the best guess chlorine chart linked in Pooldoc's sig above. It will explain the chlorine/CYA relationship and specify where your chlorine levels will have to be in order to run the pool with the CYA that you have.

Regar

[burtom]

Your CYA got as high as it is from the use of stabilized chlorine like trichlor--with trichlor, for ever 10 ppm of chlorine it adds, it also adds about 6 ppm of CYA, so over a 2 year period it can get quite high.The only way to lower it is through water waste (splashout, frequent filter backwashes, partial drains, etc). It will come down, eventually, if you do not use any more stabilized chlorine, but it will be very, very, very slowly. You can do several partial drain/refills to help it along without hurting your liner too much, but if you completely drain the pool, the liner will float and will not be able to be refilled, in most cases, which is why Pooldoc stated that #1 above wouldn't be recommended. However, you could drain some of the water--a foot or two at a time, and refill that, and shouldn't hurt anything.

Ok so I would drain the pool until there is 3 or 4 inches of water in the shallow end refill the pool and repeat this 3 or so times and then check the CYA level again. When it has normalized which is between 10 and 50 PPM how would I avoid this problem in the future? A friend helping me this spring had me do 4 separate shocks with 4 full containers about Gatorade sized of granulated Trichlor to kill my algae and that is when I saw the stabilizer level go way up on my test strips. Is using Stabilized chlorine at all a bad idea? How does one use calcium hypochlorite appropriately?

[PoolDoc]

You can drain that way, IF you make sure (a) the ground water level is BELOW the level you drain down to. (Not a problem in most of the country, right now!) and (b) that there's at least 8" of water above the HIGHEST horizontal liner covered point. (So, if you have vinyl covered STEPS, you can't drain at all!)

Chemically, you usually have to use a mixture of both stabilized and unstablized chlorine, in order to avoid stabilizer level creep.

Get a K2006, learn to use it, tell me what your test results are . . . and then I'll explain using cal hypo without CALCIUM creep. Till then, use PLAIN 6% household bleach.

[Watermom]

Ben,
He's got a K2006 and his test results are in post #9 above.

[burtom]

I have another question about beach, how do you add it to the pool? Pour slowly into the skimmer would be the obvious way to me. The next best I can think of is to pour in front of a return.

Thanks
Tom

[PoolDoc]

Using bleach alone is fine; you just have to manually add enough stabilizer to maintain good levels (probably, 40+ ppm).

Adding it via the skimmer is good, SO long as you have ZERO other chemicals anywhere in your system. Adding chlorine that way, can help avoid certain filter problems, since you regularly super-super-chlorinate your filter.

[burtom]

Using bleach alone is fine; you just have to manually add enough stabilizer to maintain good levels (probably, 40+ ppm).

Adding it via the skimmer is good, SO long as you have ZERO other chemicals anywhere in your system. Adding chlorine that way, can help avoid certain filter problems, since you regularly super-super-chlorinate your filter.

Thanks for the help. The only other chemicals I have in my system are already in my pool and my stabilizer level is through the roof so I should be good this year.

Tom

[burtom]

Chemically, you usually have to use a mixture of both stabilized and unstablized chlorine, in order to avoid stabilizer level creep.

Can a person just use 6% household bleach or is there an advantage to using stabilized Chlorine and Calcium Hypo Chloride instead of household bleach?

Thanks
Tom