i am interested in setting up my 75 gallon tank as an octopus tank. i am planning on using 80 pound of live sand as a substrate and adding 60+ pounds of live rock for him to hide in.. and for filtration i am thinking about using two Fluval Canister Filters, a Model 404(rated for 100 gallons) and a Model 304(rated for 70 gallons) i have heard that alot of filtration is a good thing a Marineland SeaClone 150 Protein Skimmer rated for 150 gallons. and 2 powerheads to create water movement.. im not sure if that is everything. if not could you please tell me what else i need. and if that is everything does that sound like a good setup? also i am buying my own r/o unit for i can just get the water from my tap when ever i need it..