• Looking to buy a cephalopod? Check out Tomh's Cephs Forum, and this post in particular shares important info about our policies as it relates to responsible ceph-keeping.


Feb 19, 2003
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.
I don't believe that the bristleworms could have taken down a healthy octopus. They usually go after already dead tissue and are great detrivores for a tank. I would imagine the already dead tissue is what brought them to the scene. Sorry to hear about your bimac :(
i agree that it is very unlikely that the worms areto blame, they just jumped on a free meal...

have you tested your water?
All f my parameters are fine, execpt for one. I found out that the hydrometer I had been using is far off calibration, I bought a new one and found the SG to be around 1.030.
Well, at least you've tracked down the probable cause. Sorry about your loss. :(

It's a good idea to measure the salinity and pH in more than one way, at least at first, to make sure your readings are accurate. You can also calibrate with your LFS (assuming theirs is accurate).

And, although you weren't having this problem, it's good to make sure your water test kits are not old and out of date.

also, make sure when calibrating a hydrometer that the water to be tested is always at the same temperature as that can chage the result

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