[monocus]

use the largest tank you can place under your tank-your footprint for your skimmer is about 5x5-so at least 6 inches of your sump will be used up-he baffles are to disperse air bubbles-usually i inch apart in an over ,under,over configuration.you will also need a return area- also good for topping up your water-the rest you can use for your refugeum.mine is laid out as bioballs-skimmer area(dry skimmer-reserve for water)refugeum,8 " space for extra pump water return for skimmer+heater,baffles and then return-using a 45 gallon tanki.in reality there is no proper or improper way to build your sump