Testing High CL Levels after Shock

[nupoolsoon]

HELP PLEASE!!

I added 12.5% sodium hypo tonight to shock and I am trying to test the CL level RIGHT now. However, after I reach about 30 drops, the water turns clear, then if the water sits an extra 30 seconds, it turns pink again. Is this normal? Do I continue to add drops and count them towards the CL level? I don't know if I need to add more 12.5% tonight or not...something seems VERY odd!!

I was quite surprised that initially I got 37 drops after adding 240oz of 12.5% bleach!!! So I started over. Wondering if I will run out of R871 like many others on this board right now. CL was at 13ppm b/f adding the 12.5% and should have brought me close to 26 for shock level.

My water is clear and I have nothing on the floor or walls that could be eating away the CL levels that quickly!! I would have to have a swamp for that to occur.

FWIW....my CL level this am was 16, I had the SWG on for 1/2 the day at 100% and at 7:00pm the CL level was 13.5, so only a loss of 2.5 for the day even though the SWG was on 100%, but only 1/2 the day.

 

[reebok]

That's normal. Why are you shocking?

 

[nupoolsoon]

I am shocking b/c I had posted under "SWG" that I thought my cell was not keeping up with generating enough CL. It is an Autopilot which has 3 power levels and I had the power cell on 3 and 100% and the CL was not being maintained. We had purchased the SC60 cell, which is oversized for our pool, so we should not need the cell power on 3. The helpful people on this fourm suggested I shock first to make sure there is not algae or other contaminants in the water. Even though my CC's were always 0 and my water clear with nothing on the walls or steps, they said that I could have something slight. Once in a while after a rainfall, I would get dust/dirt/pollen on the floor of the pool, but nothing clinging on the walls or steps, so I am shocking to rule out the possibility of contaminants and possibly rule in the problem with the salt cell.

How long do I wait until the water stops turning pink? I was waiting 30 seconds, turned pink again, added more 871, turned to clear, waited 2 more minutes, turned pink, added more 871, turned to clear...etc....will I be here all night until it stops turning to pink?

I guess when I reach my CL shock count #, which I have now, I don't care anymore anyway, but don't know if I am doing this right at such high CL levels, and the water is pink again.....now 5 minutes later.

 

[reebok]

The instructions say drop, swirl, drop, swirl right? Do it until its clear. It turns pink again if you let it sit there so just dump it when its clear if that's going to confuse you.

 

[reebok]

Maybe we misunderstood each other. It is normal for the test to turn back pink if you let it sit. So don't let it sit, or just realize that its going to turn pink again if you do. Once you finish your continuous drop swirl drop and it goes clear, you are done. Don't worry about it turning pink if you decide to let it sit there.

 

[nupoolsoon]

I am confused. I guess there is enough CL in there. Like I said, initially I got 37 drops (18.5ppm) and then it turned pink a few more times after letting it sit for a few minutes, so I was up at 50 drops, which would put me at 25ppm....I guess I will have to decide tomorrow morning after doing the overnight FC test, when the "pink turns clear" and guess if I might have lost anything overnight.

 

[nupoolsoon]

OK...missed your post. I still don't see how the drop and swirl would only get me to 18.5ppm from 13 after adding 240oz of 12.5% bleach though. Something is not adding up correctly and giving me a headache.

I am done with shocking to say the least for now. As I mentioned, my water is clear, floors and walls, steps clear and CC's with both TF Test kit and pool store results are 0. I am going with my initial gut and saying it is the salt cell which I will call the company tomorrow.

Thanks for your help.

 

[reebok]

well the main things that play a role in being off is the degradation of the chlorine (it's less than 12.5% due to age and storage conditions) or your pool volume calculation is somewhat off, or you're doing something wrong with the fas-dpd test itself. or a combination. anyway, if you want to be sure you don't have organics, you should perform the pool-school/overnight_fc_test
good luck with your swg.

 

[frustratedpoolmom]

Reebok is correct, the test will turn pink again if you let it sit.

12.5% can degrade in less than a month so it may just not be that strong, or, you have "nascent" algae that is consuming it as you add it. You can have organics and not "see" them. You can also have organics and register 0 CC. It's entirely possible that there was something present, the amount you added took care of it, and you won't have a loss like that again.

Do an overnight loss test to be sure that's not what's happening here. You don't have to shock tonight to do the test. Just make sure you test 30 minutes AFTER adding any bleach and the SWG should be off. Test again in the morning before the sun hits the pool and compare the two.

If you have no loss overnight, and the SWG still can't keep up, then it's the unit or cell itself.

 

[nupoolsoon]

So from last night to this morning my FC stayed constant at 13ppm. That's a good thing!! I plan on adding a few gallons of chlorine tonight just for the sake of it b/c we are going away for a few days anyway.

So, if I did not lose any FC, I now need to figure out if my salt cell is not producing enough CL. How can I do that?

I know my starting point this morning is 13, so what can I expect a SWG to pump out, even though it cycles and depends on the power cell too. How much FC should you typically lose during the day time hours?

Should I post this on the SWG Forum? I don't want to post too many topics on different boards and then the same questions get asked over and over.

Thx for your help.

 

[PaulR]

12.5% can degrade in less than a month

Well, that's really overstating the case. 12.5% stored at a constant 90F will degrade by maybe half in around two months. (I'm interpolating from this chart.) But you'd have to try pretty hard to store it at a constant 90F. I had 2-month-old 12.5% in my shed and it seemed to be worth about 10%.
--paulr

 

[frustratedpoolmom]

Are you picking on me?

I didn't say how much it would degrade by...Besides, we don't know how long it was stored (and in what conditions) at the store/warehouse...

Pools typically lose an average of 2ppm per day, some more, some less. Uncovered pools more, maybe 3-4ppm. If your pool is uncovered, and the SWG isn't functioning, I would expect you would lose more if it's sunny (since your FC is so high. I think Richard said something like it's a 50% loss of FC levels or something like that when the FC is elevated above normal levels.)