Everything that can possibly go wrong has gone wrong in my tank. A few years back all my coral got wiped out by AEFW. So I ran my tank empty of all coral for a year. Little by little I built it back up....then dinos resulted in another wipe out. Been fighting dinos for another year. Finally dinos gone. Then recently a huge bubble algae outbreak covering everything. So I got some emerald crabs that were quite large. They are the only thing I have added when I noticed that all fish have split fins and some ulcerated tissue on their bodies. So now bubble algae is gone but all the fish seem to be going downhill. I had to euthanize my Goldflake angel last night. Now my 14 year old tang, and a few other fish appear to have contracted parasitic infection. They are actually seeking out the emerald crabs to get cleaned!!!!! I am thinking of getting a few cleaner shrimp. But seriously, I am really thinking of getting out of the hobby. I have spent so much time (and money) over the last few years with such little progress that I am at wits end. Thanks for listening to my whining!