V2 bio phosphate reactor help??

[marinefishys]

Hi im setting up a 600 litre marine tank and so far its in a cycle was told to put my reactor on but when i opend it the contents contained silica sand some gravel stones but i bought seperatley a 250ml phosphate media, my question is do i mix the silica sand with the phosphate media and the gravel?? Or do i just put the phosphate media and the gravel?? Or just the phosphate media,, and also how much phosphate media should i put in the reactor