Check out the info in the thread below. CarlD lists an economical way to give you the higher CL testing you're looking for.

If PS100 is a Pool Solutions refill, unfortunately, refills and kits appear to be unavailable this season. If you decide you need an entire test kit similar to the full, previously-available Pool Solutions kit, take a look at the kits being sold as an adjunct to the troublefreepools website.

http://www.poolforum.com/pf2/showthread.php?t=7015