I read fish_freaks article, but I am puzzled because I am sure the clowns would show visible signs of ich by this time, or at least one fish in the tank would have some visual clue. From what I have read, dojo's are ok as long as the temp does not get above 76, so I try to keep the temp at 74 so all the fish are comfortable, but I am looking into another tank for the dojo's which will be un-heated.
The water is basically steady parameter wise, ph, nitrates, etc. It is always the same. I asked about salt settling in the sand because I have tried smaller doses in the past to relieve gill irritation, but water changes since that time should have removed it. Plus I am trying to find reasons for this behavior.
The common thread I see is that only the bottom dwellers exhibit this, and they happen to be scaleless. And I also see that a couple others noticed this problem too. I have thought about a mild dose of medication to see if it would solve this, but I am very hesitant about it. The fact that it is the bottom feeders led me to believe that it is the sand irritating the gills and the flashing is an effort to remove it. I have to keep all options open in case it is parasitic. And I would hate to have to replace the sand, this would be a major undertaking.