Can you give us size, model manufacturer of filter and pump? Maybe the pump is too big. The Quickcrete sand (according to it's label) contains particles that are both too big and too small for some filters (specifically Hayward - that's what I have).
Also tell us about your pool size, type, construction, drains returns, heater etc. and how you test. We need to know how you chlorinate and what's already gone into the pool. Sometimes floc and clarifier end up making the trouble worse rather than better.
The next thing we're probably going to ask is if you have a Taylor K-2006 and if not, we'll recommend one.