This was all good advice. I finally added about 1/2" layer of LS
last night. I DIDN'T rinse the sand and after just one "scoop" I added, the entire tank got very cloudy. I then rinsed the sand off carefully with clean (not tap) water, and waited a couple of hours. I added the rest and the it was better, but still clouded my tank for awhile. BY the time I got to bed, it was almost perfectly clear. This morning it is clear and it appears the fish have all survived.
I wouldn't recommend this maneuver unless you really, really need to, and I did. My goby had only a very light layer of sand to sift through and I needed to add it. I'm glad I did, but nothing beats being ready BEFORE you add livestock to your tank. Live and learn.