ok, this is my first post and first octopus tank i would like to keep a pygmy octopus mainly because that is what is available to me by my local fish stores. i currently have a saltwater tank with live rock and a few fish and have had it for about 4 years now, and i am 17 yrs old, thats a pretty good job imo for starting at 13 yrs old. i need to know, how big of a tank would i need for a pygmy octopus, and do i need any different equipment than is needed for a saltwater fish tank? will i need power heads? what type of filtration do most people use? is live sand or any subsrate needed? how about live rock? im very new to this, and i am willing to do what is neccesary to keep an octopus.