After keeping my bimac good and growing for four months, it died last week. I looked into the tank and saw it being consumed by at least a dozen 7 inch bristleworms from all angles. Could a large number of bristleworms overpower an octopus? Up to this point I had seen one or two worms and figured they were harmless live rock hitchhikers, and potential free meals for the octopus. Right now I am turning on the lights in the middle of the night and taking out 3+ large bristle worms a night. It is also possible that it died because of some water-quality issue, I had a lot of trouble with my chiller, and I often couldn't keep the temp below 75. I didn't use RO/DI water this time, but after running this tank for 2 months with a polyfilter added, every new water change will be with RO/DI water.