The Electronic Speckle Interferometry (ESPI) maybe applied to the observati
on of physical phenomena in transparent fluids, where variations of physica
l properties produce a change in refractive index. With this nondestructive
method it is possible to analyze the fluidodynamics in the growth tell or
the dynamics of concentration gradients in chosen points around the crystal
. Some KDP crystal growths from solution have been observed with the ESPI t
echnique in order to prove its validity.