I shocked the heck out of the water for about 5 days. I kept the chlorine levels at 20+ during that time. So far the water has remained clear. We had to keep vacuuming the sediment out to waste. Takes several days because it's so fine - like a powder. Even as you vacuum you stir it up and it blows around in the water. I think it just patience and persistence to shock it long enough to kill it all and then vacuum it all out. I'm not 100% sure I've killed it all but I guess time will tell. I bought a pool vacuum with a fine filter to help with the process.