What is killing fish?

[kenwendyb]

We have had tank 2 for 4 years. The only fish that have lived are black sailfin blennie, bristle star, hermit crabs, and snails that are reproducing and doing great. It seems as if something is killing very healthy fish. The last was a juvinile picasso and flame angel. The picasso seemed to be pulled into a rock and eaten. We have looked at pm hours with flashlight and red light and seen nothing. This has been going on for years and we cannot find the culprit. This is a 55 gal tub coral tank. We have tried live bait trapping over night and nothing. As I said the sailfin blennie has lived for over a year and goes up in all the rocks with no problem. Longest fish to live in tank was about 4 months and we have tried every shape and size fish. Thought we'd try some triggers and more agressive fish but the same results. Happy, healthy, hearty fish one day and dead or missing the next. Anyone have any ideas on what to do?

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