Mike, trust me. I would never claim to be an "expert", but I know what I am talking about here. I hate to point out a person's flaws, but Rusty (thejeweler) has ich on his fish, as well (See thread here:
https://www.saltwaterfish.com/vb/show...71#post1739271). I am not sure I would be taking that person's advice.
It is a FACT that the ONLY two things that totally kill ich are copper and hyposalinity.
I have used garlic extreme, and while it is helpful, it is not a cure. There is a big difference.
Unfortunately, you will have to take the sand out, start hyposalinity with a refractometer, and monitor the tank very closely for the next 4 to 6 weeks.
The things you will need is plenty of water made up in case you need to do a quick water change, test kits for pH and kH (as well as a buffer, in case the levels drop, which they might), and ammonia, nitrite, nitrate test kits, as well a refractometer to be 100% accurate with the salinity.