hi zapatista
for some other ways maybe, here is a link to klas's glass (scroll down page a bit for the link), I have used it many times, only downside is having to separate the glass parts of the object and load them separately... you could probably add a power fractal on top of the water shader to add some dust etc?
and 2e+008 is a very large number 2+ 8 zeros I think... and minus would be very small?
someone will have a better answer I am sure!
cheers
Jason