I am using modified DKW media which has Calcium nitrate instead of calcium chloride. Though the media looks clean after adding all the stock solution, after autoclaving I am seeing little bit of precipitation in the bottom. The precipitation get more and more with higher duration of autoclave. I am using TC agar as gelling agent. 121 degree Celsius for 20minutes. Can anybody help me to resolve this issue? And whether it is okay to use the media if the precipitation is very low?