About 6 months ago, I lost all of my fish in my 55 gal
fish/reef tank that had been set up for awhile. The fish that were in it were all extremely hardy and had been in the tank for several months with no problems. I had looked at my tank that day and everything was fine. Within only about 4 hrs from last looking at it, everything was dead and the tank was real cloudy. I never figured out what caused it and had not done anything new to the tank before they died. The corals and a brittle star survived.
The tank was drained and set back up and had been sitting for a couple of months with no fish, just the corals, star and live rock. During this time, I've had a LARGE increase in bristle worms. I'd seen them before but not as many as I had now and the majority of them were now staying out in the light huddled up on two adjoining live rocks. A few days ago I added a damsel to see how did in the tank. I also added some Salwater BioZyme (cant remember if I did this last time). I watched for a few days and everything was ok so I decided to get a hogfish to help take care of the worm problem. When I came in with the new hogfish, the tank looked like the botttom had been disturbed as I noticed it was a little cloudy with what looked like some grains of the bottom sand floating around in it. It was perfectly clear when I left less than an hour ago. I added the the hogfish and after less than an hour, both the hogfish and damsel were dead. The tank was still cloudy and I still had these small things floating around in the water that I had figured would have settled. I looked at them closer and gathered a few from the water and discovered that they weren't sand grains, they were tiny worm looking bugs curled up in balls.
Does anyone know if these are bristle worm "hatchlings" or something else and could they kill off a tank like this?? Or has anyone experienced anything like this before??