I recommend not moving the rock set it up and leave it alone, every time you move it you may be causing a mini spike due to all the gunk from feedings that have been decaying under the rock and what not being mixed up into the water mass this can also be causing a bloom in the tank besides the sand or other debris. I know it is hard to leave it alone but it will save youproblems in the long run. and also it will settle haturally as the nitrifing bacteria catch up with the added AMMO, I don't recommend putting unnatural in the tank, just be patient.
Just my .02
Paul