Looking for pool shocking information from Ben Powell.

[burtom]

That's a really odd reading for the CYA. How did you get that result?

Here's the Taylor video: K2006 Cyanuric acid (CYA) test

I added 3 cups of distilled water to 1 cup of pool water and did the test as described. 7 mL of the diluted water and 7 mL of the agent and multiplied the point where I could not see the black dot by 4.

Thanks
Tom

[PoolDoc]

results are:
FC 1.6
CC 0.2
pH 7.7
TA 160
CH 140
CYA 228

Ok. Well, your water is OK, except for the super high CYA. Here are your options, 2 with draining, and 2 without:

1. Drain and refill. This is NOT recommended on a 20 year old vinyl pool.

2. Do an in-pool drain and refill. Slow and requires a vinyl winter cover that's about 12' wider than the pool on all sides.

3. Run a HiC2 pool -- high chlorine to compensate for your high CYA. That's OK, but it means NORMAL chlorine levels will be around 15 ppm on your pool and shock levels will be about 30 ppm. This should be pretty easy with the K2006, so long as you have no algae. But, to get rid of algae might require FC = 60 ppm!

4. Run a sorta HiC2 pool -- high normal chlorine (15 - 20 ppm) but with sodium bromide and polyquat on hand to use, instead of having to push FC levels to 30 or even 60 ppm.

If I were you, I'd opt for #4, but it's up to you. Regardless, with options #3 or #4, you don't want your CYA level to keep climbing, so you've got to switch to bleach (or 10 - 15% 'liquid pool chlorine', if it's available) OR calcium hypochlorite granular. Using calcium will require special methods -- not hard, just different -- to avoid replacing high CYA levels with high calcium levels.

One HUGE downside to the HiC2 method: if you let your pool get slimed over the winter, there is an good chance that the CYA will be converted by bacteria to ammonia over the winter, leaving you with so much ammonia that it would literally take 400 ppm FC to clean up in spring. So, you can NOT allow the pool to slime over the winter. Closing clean, plus using repeated polyquat doses over the winter, plus Minnesota temps should make this easy, if you just pay a bit of attention to the pool after closing.

Lemme know what you want to do.

[burtom]

Hi Ben:

The pool is 20 years old but I did have the liner replaced last year so I would like to hear about option 1 at least and what it consists of if the new liner helps. The question I have is how did the CYA get this high? Was it using the Trichlor shock and Trichlor tabs? I mean the water in the pool is only 2 years old. What steps should I take to keep this from happening again assumine we get it straightened out?

Thanks
Tom

[burtom]

Hi Ben:

I guess I would also like infomation on 3 and 4 like what special procedures with the Calcium Hypochlorate and will the CYA ever drop?

Thanks
Tom

[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]

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

[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