I have a 40 gallon tank that I just took down last night. It was a freshwater tank that I housed two rather large oscars in. I have been looking into getting a saltwater tank and getting an octopus. I have had freshwater tanks for over 9 years. I have a 55 gallon heavily planted freshwater tank. I was wondering what I need to do to house an octopus. The tank is 40 gallons. I have two fluresent 20 watt bulb in a fixture for this tank, would that be enough light, or should I go ahead and buy 2 55 watt cf lights? I have a glass top. The filter that I had for the tank is a hang on back filter (Tetratec PF300 Power Filter). I would like to start putting in live sand and water sometime tomorrow. I read that it takes about 3 months for the water to get stabalized? This seems like a rather long time. I was thinking about getting a large piece of lava rock for this tank and carving out some caves and places for an octopus to hide. Would that be ok or should I buy some live rock. Also are there any kinds of fish that will live in the tank with the octopus or can I have more than one octopus in a tank? I really do not know much about cephalopods but I am going to buy a book and read up on them. I do want to get the water in the tank tomorrow. Any help would be great. Thank you.