Just to clarify heres the directions on the container, Six drops of Phosphate Control will lower your phosphate by 1 ppm (mg/L) for every 10 gallons (37.9 liters) of water. Does that mean 1.0 ppm or .01ppm? My phos is testing at .04 on Hanna and I was going to dose 72 drops. My tank volume minus rocks and sand is 120 gallons, so 6 drops X 12 = 72 drops to drop my phos by .01?