Another high CC pool

[drmac22]

Split from HERE by moderator. jblizzle

I am having the exact same problem with my pool after I opened it. I showed no FC in the pool and the cc was showing at like 7.5 so I started the shock setting at 24 in the calculator because that is what the chart said with the CYA at 60 like my pool was. it was a 7.4 ph. have been putting bleach to try and keep it at 24 but it is not staying there and the CC numbers have climbed to 14 or 15. Now I am working on it on the half hour to try and rid the CCs from the pool. When I test for the FC levels now I do it just as the instructions state, put the heaping scoop of the power in the 10ml and use the stir to mix it, it turns pink but not a dark pink, then I drop one at a time the 871 until it turns clear. the problem is it turns clear then it slowly shades back to pink. I add another drop does the same thing, up to like 30 drops then I stopped. I added the 003 reagent and it still showing CCs Am I doing something wrong?

 

[chem geek]

Did your CYA drop over the winter? Was the 60 ppm what you measured on opening or are you assuming it's the same as when you closed?

You are doing the right thing and it can take extraordinary amounts of chlorine if bacteria converted CYA into ammonia. As noted in this post, it took cumulatively 56 ppm FC of chlorine to get rid of ammonia and partially degraded CYA from my pool.

Your FC keeps going from clear to pink because of the high CC that is bleeding through. You probably have nearly zero FC because when you add it to the ammonia in the pool it forms monochloramine almost immediately and that shows up as CC.

 

[drmac22]

It was at 60 when I opened it. 0 FC. Yes I believe that is what happening with the FC. the ammonia is bleeding it over. Just checked the shock level and it is at 22 now for FC. The Ammonia is still presents with the test. 1.0 and the CC is lighting up now its at 4.0 so I think its working. Thanks for the advice!

 

[drmac22]

Well this morning the pool levels were PH-7.8, CYA 60, TA 130, FC-20 but still showing 1.0 ammonia and the CC still registered at 5.0. I did the CL test with the five drops into the gauge and it showed up orange so I know there is a very high level of Clorine in the pool. Can't figure out why its still not killing off the ammonia and lowering the CC. I cleaned the filter this morning and it was pretty dirty so it must be doing damage to the junk in the pool. the Pool cleaner ran all night. Do I just keep doing what I am doing and try to keep the slam up at 24 like recommended or let it start to drift down? Its saying to add a little muratic acid to lower the PH to the goal level 7.5 should I bother with that or what?

 

[JasonLion]

Don't worry about, or adjust, the PH while FC levels are that high. The PH test is not dependable while FC level are very high (anything above 10 can be an issue).

You want to maintain shock level until CC goes down to 0.5 or lower. Your CYA level is going to slow down the process a little, but things will move along, CC and ammonia levels should both continue to fall from day to day.

 

[drmac22]

Will I need to maintain that level every hour or can I let it run its course and just check it a couple times a day?

 

[JasonLion]

Since the FC level isn't falling all that quickly, hourly is overkill. It might help just a little, but probably isn't worth the extra effort. If you can aim for two to five times a day that should be enough at this point.

 

[chem geek]

Because of the factor of 5 difference in ppm N units used for the ammonia test and ppm Cl₂ units used for the FC and CC tests, a 1 ppm in the ammonia test would be expected to read as 5 ppm in the CC test. The ammonia test measures the sum of ammonia and monochloramine and does not distinguish between them.

Since chlorine in the presence of CYA oxidizes ammonia over around 4 hours, I think what is happening in your case is that you have partially oxidized CYA which itself does not register in tests but which gets slowly oxidized and in doing so produces ammonia which reacts with chlorine to quickly form monochloramine. So you may find that you have this CC reading for a few more days. You can see in this post when this happened in my pool that after the FC started to register, it took around 4 days before FC usage became normal and the CC went down.

 

[drmac22]

Well I went on travel for work for 2 days and had my daughter add 2 gallons of bleach on the 2nd day. When I got back I checked the levels. the Ammonia was 0.5 and the CC were 0, the FC level was still at 21, my pool test kit that checks the chlorine and PH showed 7.5 on Ph and the Chlorine was orange vice the normal yellow t usually is. I guess cause the chlorine is so high. My CYA was 50 and the TA was at 140. So I think it did what it was suppose to. I am going to let the chlorine levels drop and Aerate it to try and lower the TA some. It basically went a full day with out adding chlorine and still stayed in the 20s. Water is crystal clear and the pool bug is running to clean the brown power off the bottom. I will brush it down again this evening and then I think I am ready to start heating it and getting it ready for the swimmers! haha Thanks for the help this is the reason I love this place.

 

[chem geek]

Congratulations! It sounds like you got to the end of this and it didn't take too long.