Sometime in the next few months, I'll be moving into a house. I don't know which house yet, but my husband and I are on the market, and my two big musts are a big yard for gardening and a concrete foundation so I can have a large tank. I'm thinking 150-250 gallon range (I want it to be at least 6 feet long), and I want it to be a well planted rainbow based community. I've been scoping out big tanks on craigslist, and most of them have holes drilled in them for sumps and overflows and to be honest...I have no idea what those are or their purpose. I've never owned a LARGE tank, so I'm not sure what I need to be looking for. I know I love my simple AC110, but I know I'll want something other than HOBs when I upgrade the tank. I know canisters are often recommended for planted tanks, but would that be enough on this large of a scale? I'm coming here for help understanding what options there are and what works best as far as an efficient, simple, dependable filtration setup for a large, heavily planted FW tank goes. Also of the utmost importance, I need to know whether I should stay away from tanks with holes or if those holes are going to make my life a whole lot easier and why. Thanks!