I don't think you have to actually replace the water. There are lots of
folks with salt water aquariums. Go to a good pet shop and talk to the folks
there about a salt water set up. I think you will find they are not cheap.
Or even faster go to google.com and search on "salt water aquarium".

Charlie



"L. A. Powell" wrote in message
news:lpLbb.548326$Ho3.95679@sccrnsc03...
Unless you have a steady supply of fresh salt water that replaces the
existing salt water, with its fish waste, three days is about all one
could expect.