How often are you testing and adding bleach? Does your chlorine ever drop down to 0 before more bleach is added?

Try shocking the pool up to 12 in the evening after the sun is off the pool. Then, get up early and test it before there is sun on the pool. See how many ppm of chlorine you are losing overnight. If you are losing more than 1ppm from sundown to sunup, then you are fighting something in the water.

Also, we recommend running the pump 24/7 while you are trying to clear a pool.