Further, some in-line chlorinators work extremely well, and others clog up easily. I'm not sure they actually work any better than a $10 floating chlorinator with an adjustable vent.
I generally rely on bleach/liquid chlorine, but the last two seasons more on my salt-water chlorinator. However, early in the season when i need stabilizer, I will toss in a floater to add a stead flow of both chlorine and stabilizer.

A more important investment, though, is a proper test kit. You'll see in Watermom's signature a place you can click on "Get the testkits you need".