G'day Whilst I'm still a few months away from owning my Octopus I have certainly, effectively, cemented in place just how everything is not only going to run but also aquascaped to, I do intend to have 'coral' with my Octopus but no other inhabitants and the 'coral' I have chosen is all Leather / Non Stinging Corals. The only reason that this tank is NOT up and running already is simply because it is the 'luxury' side of a much larger build and effectively the very smallest part of the builds overall entirety, not matter how large this Octo Build sounds... SYSTEM LIST:- Display Tank:- 48"Lx24"Wx36"H @ 170G est. Equip Sump:- 36"Lx18"Wx18"H @ 85G est. Refug Sump:- 48"Lx18"Wx18"H @ 55G est. RO/DI Reservoir:- Food Grade Drum @ 58G est. Skimmer:- LifeReef VS3-72" 1500Gal est. Reactors:- At least 1 for Carbon. Lighting Disp:- ReefBreeder Photon 48" LED Fixture Lighting Refug:- ReefBreeder Value Custom LED Fixture Return Pump:- Laguna Max-Flo Power Jet 4280 - 16500lph ATO: AutoAqua Smart ATO System Powerheads:- 4 to 6 Tunze Nano Stream 6015-6025 LIVESTOCK:- Octopus:- O.vulgaris Coral#1: Green Star Polyp (Briareum sp.) Coral#2: Gorgonian (Photosynthetic) Coral#3: Stereonepthya (Photosynthetic) Coral#4: Stereonepthya (Photosynthetic) As far as the tank goes itself and 'Octo-Proofing' it, the lids whilst I am not going to say I'm not worried about, they are however easy to fix/seal/lock/etc. Overflow Design What mostly concerns me is my design of overflow and how best to prevent the Octo from going into it, thankfully the design is easy to describe...it's the ENTIRE rear wall of the tank, like a fake wall but just black acrylic and well an Overflow with teeth at the top, I am just concerned about how best to 'Octo-Proof' the Overflow ? The powerheads will not be a problem with what I have planned in mind, working with another unique creature so diligently over the past 5-6yrs has given me understanding in general of many marine predators and their overall certain specific needs that match one another. Birdseye View The 3 landscapes within the tank (1 in each rear corner & 1 slightly larger in the rear center) are 'DIY Premade Octo Dens', these Dens are designed for the Octopus to utilize as a resting place / home similar to what they would have in the wild, something with a narrow entry/exit but larger interior. However to take it a step further and to add to the overall filtration or rather "quality of water" within each Den itself, a power head will be position beneath the above Octopus Den and SAFELY & SECURELY divided separate (but still allow flow), what this will do is suck water from the above Octo Den and then push the water back out into the Display keeping the water within each Octo Den new and fresh, whilst the divider keeps the Octo from harming itself on the Powerhead. I'm not a new reefer I have served my time :) one of the reasons I now fancy what most do not is because I have kept so much of what others still love and find fascinated by....after all it did NOT take me much reading to become consumed by the Stomatopods and then intern after half a decade become... The Mantis Man.