Since your CH is fine for concrete, and your pH is fine and stable, do NOT worry about T/A. Let's leave that for now.

I'm with Lisa: there are questions.

Power Powder seems to be Cal-Hypo, which, if that's what you chlorinate with explains why CYA (stabilizer) is 0, but doesn't explain why CH is only 200ppm, but that's OK for now.

To calculate your volume, it's basic high school geometry: Length * Width * Depth (of the water). That gives you cubic footage. Multiply cubic footage by 7.48 to convert it to gallons. But if the pool is more than a simple box (such as it has a deep end) you have to break it into chunks you can calculate the volume of, then add them together. Pump and filter size isn't enough. Sorry.

Next you are going to have to "shock" your pool. That means raise the Free Chlorine level. Personally, since you have a concrete pool, I'd go well beyond shock level (which, with CYA=0 is about 10 to 12) and hammer it up to 20 or even 30 (don't swim in it when it's that high). We don't normally recommend this because it will fade a vinyl pool liner..but you have concrete.

To do this you can use either bleach or Liquid Chlorine -- LC-- (sometimes called "Liquid Shock" but ONLY use it if it contains Sodium Hypochlorite). Bleach and LC are the same thing but you can get LC in double the strength of "Ultra Bleach". UB is 6%, LC can be up to 12%. I figure if a gallon of 12% is less than 2x the price of Ultra bleach, it's cheaper. You can pour it in the skimmer or, as I prefer, into the return stream while the pump is running.

You'll need a lot of this stuff, but I can't tell you how much without knowing at least roughly the pool volume. 1 gallon of 12% LC will raise 10,000 gallons of water by 12ppm, but will only raise 20,000 gallons by 6ppm--simple arithmetic.

I look forward to more info.

Carl