Any advice welcome...

[gecmom]

I recently lost a black clown and coral beauty to ich. It's my first experience with it so I think I reacted too slowly. I have a 16g w/ live rock and sand, a couple of feather dusters and a handful of crabs and snails. All have been living peacefully together for about 4 months. I think the problem started when I introduced a boxfish about a month ago--he only lasted 3 days but they all seemed to get along fine. My fish guy says my water quality is good but now I have a fishless tank. I started with a reef safe ich remedy. Should I continue the treatment before adding anything new, and does anyone have any thoughts on what may have made them sick? Thanks,