In addition to Marie's and Watermom's advice (which is great, as always) you need to have your pump/filter running 24/7 until your water clears. Shock levels will kill whatever algae you might have in the water, but will not remove it from the water--your filter does that. Same thing with the Ca precipitation. If that's your problem, (and it sounds to me like the problem may be a combination), the filter is what will take it out once the chlorine kills.

Janet