I just want to already thank you all for the information you've already given to us, and this is my first post! We are converting to chlorine from Baquacil after wintering. Our pool store told us to drain it and shock the water that we left in the bottom, but that seemed counter intuitive since if you can shock that water, why not all the water? And everything we read said don't drain an above ground pool unless you have to, because it's dangerous to do yourself.
We bought a house with a pool, had the pool professionally opened (without chemicals) so we could see where things went. The previous owners used Baquacil and the water is beautiful after wintering with no algae and no slimy feeling on any surfaces. But we don't want Baquacil due to cost, the many multiples of stories of people liking it one year and hating it the others (they only used it one or two years), and the fear that as new pool owners (neither grew up with a pool either) that if there is a problem we would not be able to easily fix it. So, no Baquacil.
We simply HAD a large bucket of cal-hypo from Walmart (HTH brand) so we are using that instead of bleach. If we use this up, we'll go to bleach. We used the pool calculator online to figure out how much to add to raise the free chlorine to 10ppm, 33 ounces. We have an above ground oval 28 x 16 x 4ft deep pool so from what I understand, with a vinyl pool 10ppm is what we're aiming for until this is done. (Right?)
As soon as we put in the cal-hypo, the clear water turned a cloudy green. So, now we're going to be testing and watching the colors turn! We hope we don't ruin it!