I really think you need to add chlorine - your cya test doesn't give enough info - but even if it is at 50, you need to have your chorine higher. Your fc in one test was 0, and in the other 1.5. Either way you probably have algae which is why your pool is cloudy. If you added a quart of shock, and have tablets in your floater, then something is eating the chlorine. Using stabalized tablets is what is raising your cya - You need to add chlorine in the form of bleach - what kind of liquid shock did you add? Was it a peroxide shock?