You should find that the little bugers eat a lot and grow fast. Octopuses need to grow fast to obtain their adult size in their short one to two year life span. You should also know that octopus eggs can be artificially reared. Use an airstone to provide a gentle current to keep the eggs well oxygenated and to prevent fouling. One reason that you might want to do this is so you can raise some of the eggs at a higher temperature.
Octopuses can be either batch reared or reared in individual containers.
With a little preparation, luck, knowledge, and more than understanding loved ones, you can raise octopuses in your home. Just think, you could train a whole army of them to wash your dishes or steal documents from high security FBI crime labs. References Boletzky S. v. and R. T. Hanlon. A review of the laboratory maintenance, rearing and culture of cephalopod molluscs. Mem Natl Mus Victoria.