After a long research I found that the majority of the credible sources
endorse if not promote the use of fresh ocean waters in your aquarium.
Nevertheless, there is a slight opposition to this option by many. This
objection is worst considering...
For example, the Complete Encyclopedia of the Sal****er Aquarium by Nick
Dakin (page 86) recommends against it with many valid reasons...
1. Logistically difficult to many aquarists without easy access to a water
source compatible with their fish. Tropical fish may not have the natural
means to fight off pathogens from cooler waters.
2. Finding a source of unpolluted waters may result impossible specially in
industrialized countries.

I have to add that the great majority of sea dwelling creatures include in
their life cycle tiny or microscopic larvae and eggs. This stages of
potentially dangerous species may enter your tank unseen. On a plankton
sample taken near Mona island in Puerto Rico, hundreds of miles away from
any river or developed area, I found TMTC (Too many to count) species of
parasitic copepods, Callinectes spp, Panulirus spp, Hermodice spp, hydroids
and others to include shark eggs.

There is a risk in using crude sea water/sand/live rock.

Thanks!


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