  It is argued that the short time scale phenomena can be studied within the
framework of hydrodynamics in the quark-gluon plasma. There are two different
versions of the hydrodynamic-like equations in the literature. In this work we
discuss the possible relationship between these versions. In particular we show
that if the colour charges associated with the velocity and density matrices in
the matrix version of hydrodynamics are same then both the versions of the
hydrodynamics become identical.
