my friend will sell me a 75gal hex for a good price w everything. i would be buying this tank for an octopus, but was wondering what everyones ideas are on this idea. what would some pros and cons be? thanks for any advise!

All things being equal, it's usually better to have a longer, wider tank that is less tall. But since it's a 75 gallon, there's room for an octo such as a bimac. A deeper tank is harder for you to take care of, too.

If you buy a used tank, make sure that no copper treatment has ever been used in the tank - that would be fatal for an octopus.

Nancy

I used a qaurantine tank for my octo. He has been in there for about a month. The tank was used to treat fish with copper. The octo seems very healthy. He eats a lot and is active at night. Im worried about Nancy's commment about not using a tank with a copper history. Has anyone else used a tank used for copper treatment?

No, I have tried to avoid it at all costs.

I beleive it was Roy (Neogonodactylus) who had problems with Blue rings being kept in a system with copper treatment history.

Better and try and upgrade soon ;)