I just upgraded your registration . . . and Googled the address you gave when you registered. (Don't worry -- I'm the ONLY one that can see that address.) There's a pool there too.

Check the pH on it (after you verify the kit) -- a plaster pool like that can be SERIOUSLY damaged by extremely low pH. You may need to go borax and washing soda hunting at Walmart tonight, if you have to work on the pool. But don't leave IT in the yellow range, either!