Ok everyone I decided to dig into my wallet and get a skimmer rated for 250-300 gallons for my 125gal, my only problem is wondering if I can hook up the plumbing to draw water from my tank because I won't have a sump, is this possible for external skimmers? The model is the reef octopus 8" Recirculating skimmer. Before I purchase this I would like to know if this is possible without a sump and if that's what external skimmers mean? This will sit directly next to the tank because I have about two feet next to the tank for it. Please help