hello there ppl

i was wondering.. what kinda rocks/sand to use for aquatic plants, planted tank.

i bought this awhile ago... and im using it now.. can fellow sifus here please help me identify what kind of sand/rocks are these... should i buy more (cos im upgrading from a 1.5ft --> 2ft tank).. or should i buy others ? and how many KGs would i normally need for a 2ft tank.. plz help out sifus