Hi Bruce and welcome to the Pool Forum. Can you post some current water testing readings for us taken with a drops-based kit and we'll try and help you figure out what is going on with your pool. Make sure the CYA reading is one of the levels you report for us. Also, tell us the exactly what all you have put in the pool -- meaning ingredients and not just "shock." Have you had an algae bloom? How often have you been testing and how high have you been taking the chlorine? Also tell us what type of filter you have.

Repost with the requested info and we'll try and help you out.