This chart may be help you decipher those high chlorine readings since they are higher than your OTO tester can differentiate:

http://pool9.net/oto-chart/

Pools with low CYA lose chlorine pretty fast. Continue to use dichlor for a little while longer until your CYA is around 50. Then you'll want to switch to just using bleach otherwise your CYA will get too high. (Don't test CYA too often or you'll use up all your testing reagent.)