If you've been using dichlor -- a stabilized form of chlorine -- it's VERY likely you have rather high levels. The "Best Guess" page linked in my signature explains what's going on. You will have to have a K-2006 test kit (test kit info page ALSO in my sig) in order to measure and manage your pool levels. (There are other kits, but they cost more) Dealer testing is usually NOT trustworthy, and the only way to tell if your dealer is the exception to the rule, is to test it yourself and compare. But, once you can do that, you don't NEED his testing.