Great site. Found it last year and my compliments. Here is my story.

First the good stuff.

Above Ground Pool 18 x 33 ~ 16,000 gals - Vinyl Liner - Constructed last year.
DE Filter - Full Sun 75% of the day.

I was given free Baquacil chems and used them for the first season last year. No problems at all. Started this season with a good start and then the pool got cloudy about June. Used up all the remaining Baq chems I had and then decided to convert to BBB. Dumped in bleach, watched the pretty colors and then the water was clear. Had tons of Baquagoo and vacummed it all out. Changed DE about 3 times and then pool was crystal clear. DE filter has been running great for about a month with no pressure increase. Pool has been crystal clear ever since.

I have the Taylor Test KIT which can check for PH, CL, TA, CYA and CH. So here are my current #'s.
PH - 7.4
FC - 0
CC - 2
TA - 70
CYA - 60
CH - Low - doesn't really bother me since I don't have a plaster pool

I am using 12.5% liq chlorine which I add about 50 oz every other day.

After reading everything on this site and the conversion instructions I am still stuck on why my CC is still high. After I add the liq chlorine at night and test about after an hr and my FC is about 3 and my CC is 5 which is what I expect. The next day my FC is 0 and my CC is about 2-3. I know what I have to do is to shock the pool and raise up the FC high enough so I can pass the overnight test FC test. Problem is with only a few more weeks in my pool season (live in PA) I don't want to shock the pool only to tell the kids they can't swim for a few days.

Here is my question.
What is the problem with continuing on with a CC level that will not drop to 0 and my FC level that doesn't last?

I have no problems with the pool and the water remains crystal clear. I still add 50 oz of the 12.5% liq chlorine every other day.

My plan would be to shock the pool at the end of the season for closing and then deal with the CC at the beginning of the spring.

The problem I see with it is twofold; (a) you've got something consuming the chlorine, whether it be algae, left over baq ****, or some other organic - something's in the water. (b) When your FC goes to 0, you have no chlorine for santitation for killing bacteria, pathogens, and whatever's consuming your chlorine to begin with. Personally, I'd shock the pool, but then again, I don't have kids that want to swim in my pool. I don't have any qualms with swimming in FC levels up to shock level, but you have to go with what your comfortable with. At the very least, I would add enough extra chlorine to compensate for what's being consumed so that your FC doesn't drop below the minimum for your CYA level.

Just my .02.

Can I "Amen" what Mike said?

I'd go ahead and shock it now. If you do it right and consistently hold the FC to shock level you're probably only talking a couple of days.

I'm also like Mike I'm comfortable swimming up to shock level.

I'll second the last part too

...and with a CYA level of 60, your shock level is 24 - if you don't reach and keep a level near this, you're only feeding your chlorine to whatever is consuming it.
Personally, I'd rather swim in shock-level chlorine than in zero FC.

Shock the pool in the evening before bed, the next day let them swim. It's perfectly safe to swim up to shock level, some report swimming at higher and not melting ... (High CC's can cause irritation to swimmers.)

Tell the kids in no uncertain terms that they are not to pee in the pool, otherwise the chemistry is off and they cannot swim until it is correct.

Then tell them that if going inside is too much trouble, then they can go over there by the hose and pee in the grass and then wash off themselves and the grass with the hose before getting back into the pool.

Ok thanks for the advice. I'll go ahead and shock since it will be a rainy weekend and let you now the results.

I think you need to read some articles in pool school

You say your pool is 16,000 gals & you add 50 oz of 12.5% every OTHER day

You also say your FC is 0 the morning after you add your chlorine.

In 16,000 gallons 50 oz of 12.5% only raises your free chlorine 3.1 ppm

With a CYA level of 60 your FC should never drop below 5 ppm

Your chlorine level is 0 at least 75% of the time & under you minimum of 5ppm (safe sanitation level with CYA of 60 ppm) 100% of the time.

thanks for all the advice. I went ahead and shocked the pool. Everything is all good. Chemcicals are in balance and my CC has droped to 0.

Thanks for the update