changing existing substrate

[dat673]

would like to know the best way to change the substrate I have for something different in a saltwater tank

 

[sikoko]

nothing to do but take the fish out for a little while you scoop out the old and put in the new

 

[fisher12889]

I would use a gravel vac to clean the old gravel thoroughly before removing it with some sort of cup or something. Then I would just pour the new (rinsed) substrate in the tank carefully.