My indoor vinyl pool has very high CYA levels -- should I drain it?

I have taken care of my pool for 21 years and have seemed to run into a snag that I never have had before.
I test with Taylor kit 2006 and these are my current readings:

PH 7.4
TA 180
FC 25.5 yes this is true I supershocked last night with calcium hypochlorite
CC 1.0 only budged .5 after following calculator recommendations.
CYA 180
CH 130

I have a 16x32 inground vinyl pool. I have been unable to get my chlorine levels down in over a month and realize that this is due to the CYA levels from having used Trichlor tablet over the years. Last year I switched to the BBB method but would occasionally put a puck in the skimmer to keep chlorine levels up as I have many kids coming in and out of the pool. We fill with well water and I tested the water yesterday and found the TA levels to be 320 which explains my increased levels. I have been slowly bringing it down with Muriatic acid but don't seem to be making much headway as I get it down and then need to add water due to loss. We have a building over the pool so not much chlorine is loss due to sunlight.
I am just wondering if I need to dump some water again and add new but then worry about the TA levels going back up. In looking at the CYA/Chlorine chart I see my numbers are not terribly out of whack but I don't want to increase the chlorine in fear of getting too high. I usually shock with bleach but am using the hypochlorite to avoid adding to the FC number. Am I wrong in this? Any help would be appreciated as I have never had this kind of problem in 21 years.

Any kind of chlorine will add to the FC when you put it in the pool.
Sunlight is one of the things that help clear CC. Maybe a UV system might be useful in your pool. We usually tell people to avoid or shut them off on their outdoor pools but if your pool gets no sun...

I don't know if this makes a difference but the building is "see through" and has doors that open at the side. We have had little sun here in North Idaho so have had the building closed. It is suppose to get up to hundred this week so I will open up the building with hopes the sun will burn up some of the chlorine. For now I will not empty and see what happens. Maybe this is why I have had problems as it has been cold and wet this year more than usual and the building has been closed? Who knows. I scratch my head daily wondering what went wrong. There has also been work done on the well system over the past year in the neighborhood and anything can be added for all I know. We have a water filter on the system to help get rid of contaminates. It has helped some with the TA.

Does the sun shine on the pool water when the building's open?
I have to tell you that very few people on this forum have any experience with indoor pools and I'm not one of them.

I'm going to ask Ben to look at this thread.

I have gone ahead and emptied part of the pool and am refilling. We cleaned out the sand filter by washing it thoroughly with water to hopefully get rid of some of the stabilizer. It was pretty murky white. I have tested chlorine levels at the halfway point of refill and the total chlorine is now 15.0. I will test everything once pool is full. I have had the doors open with sun hitting it this afternoon and hope that will deplete some of the chlorine as well. I hope this takes my CYA levels down to a more manageable level for balancing chlorine and not having to supershock at such high levels. Wow! With all the researching I have done I feel I could have a chemistry degree :). Sure appreciate all the information here. I guess after 21 years of pool ownership and no major problems I feel pretty good. I have been thoroughly educated and an education is worth much to me whether it be in pool maintenance or??? I guess I will need to read up on winterizing as we always floated pucks in the water and me thinks this is how the CYA increase happened. Thanks :)

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Originally Posted by swimnfun

I have a 16x32 inground vinyl pool. I have been unable to get my chlorine levels down in over a month and realize that this is due to the CYA levels from having used Trichlor tablet over the years.

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I don't know if this makes a difference but the building is "see through" and has doors that open at the side. We have had little sun here in North Idaho so have had the building closed.

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+ Do NOT use trichlor on an indoor pool. Do NOT use dichlor on an indoor pool with CYA > 50 ppm.

+ If you use cal hypo on an indoor pool, you MUST learn to how to *SAFELY* add it to the skimmer, or you will have other problems.

+ If your pool and equipment is salt-compatible, that would probably be easiest.

+ Bleach will be next easiest. Cal hypo will work well, but ONLY with a sand filter, and ONLY if you learn how. Following the label on the bucket will NOT work well, long term.

+ Do NOT worry about 1 ppm CC levels on an indoor pool. If anyone swims in the pool, you probably won't get lower. What will lower the CC levels is direct sun (or a UV system!). Combined chlorine compounds that appear in indoor pools are usually NOT the simple chlorine + ammonia compounds described in the pool industry literature.

+ As rule, it is NOT safe to drain vinyl inground pools. It sounds like you've dodged that bullet, but if you drain too much, you'll lose the liner.

Thanks for all your advice. Tested today and everything is great!!!! I have a SI of 0. CYA came down to 110. I use bleach so all is good there. Yes, I am very aware of the emptying vinyl pools as we learned the hard way about 10 years ago. Dumped just enough to go below jets and then refilled and it was enough to get numbers at a more manageable level. Pool looks great and feels great. My true test is that I can swim without goggles. I guess I just needed a new experience ;) in managing my pool. I am even more knowledgeable and your site has helped me greatly along with the Taylor kit. Onward I go into the deep blue of my pool!! Have a great summer everyone and be safe! Diane

Glad things are working out for you!