ok to be more specific, i plan on keeping a bimac in a 30 gallon tub, with about 15-20 pounds of coral rock some pvc pipe for him/her to have fun in and explore and a huge lego block and a couple of containers for him to hold onto, a good protein skimmer like some kind of venturi and feed him different shrimps sound good or different ideas to help let me know:)thanks

As long as you follow the general rules for setting up an aquarium and apply them to the tub then it is the same thing.

I have 2 points worth considering though.

Some tubs are made out of a material that will leach toxins into the water because it is saltwater and poison an octo.

Also, by not using a glass tank you will miss out on a lot of activity that people mainly keep octos for. So seems a shame to not be able to sit and watch through glass?

Is the tub going to be a refugium?

Cheers
C

Colin has made some good points.

I've also wondered how you would properly secure the tub so that the octopus couldn't escape, and how you would provide lighting.

All things considered, it might be easier to use a normal glass tank rather than a tub.

Nancy

Just a little addition,
I dont know if the 30 gallon tub would be much less expensive than a 30 gallon aquarium. I live near a big supplier but I can get 40g acrylic aquariums for like 50$. Thirty gallon aquariums are probably close to 35-45$. But if you have a good reason for the tub it would work.
JJ

keeping an octopus in a tub prevents u from seeing most of its activities(playing with lego block and feeding) i agree wif nancy, a normal glass tank will be easier.

Also, use a netting to prevent it to coming out. but if you do this, this will make it even harder to see its activities.