I know what you mean about the pool stores trying to get you to buy a bunch of stuff. Resist! It would be a great idea if you could get your own test kit that will measure higher than 5. A little pricey initially, but well worth it and will pay for itself quickly. We like the Taylor K-2006. If you buy it from Amazon through the following link, not only do you get the great kit but also the Pool Forum makes a little money, too.

http://www.poolforum.com/pf2/showthread.php?t=10006

If you are going to do a water exchange next week, I wouldn't worry too much this week. After the exchange, we'll help you get things cleared up.