Pooldoc's advice to drain and refill IF you have clean clear fill water with no metals is the easiest and quickest way to clear up the pool....but if you have well water, or stream water with metals, then it's a real nightmare to try to manage a new fill, and would make it easier to possibly try to work with what you've got.

You can empty the pool, scrub down the liner with baking soda and refill, as long as this is one of the plastic-type one-piece pools and doesn't have a separate liner. When you drain a liner pool, the liner generally doesn't stretch back out again and will have to be replaced. Also, if you're going to start over again, you'll need a good test kit in order to get your water re-balanced, so you don't have to depend on the pool store tests and their advice (you've already seen how well their advice works). And by "as few mystery chemicals as possible" he means none of the pool store goop where they're not just selling you chlorine, or stabilizer, they add other stuff into it that has unpredicable results in the pool (such as what happened when you added a huge dose of clarifier).