So you are talking roughly a 317 gallon tank that is 5.2'L x 3.3'H x 2.5'D. You wish to water changes of 5 gallons every other day. To me that would be too often. It appears you wish to keep a refugium. Is a sump also in the works? For the amount of fish you wish to keep, you will likely need a...
It depends upon the brand. For the size tank you are looking at you will probably want to go with a skimmer from Lifereef or Euroreef as those seem to be the best on the market right now. They are not cheap but, from what I understand, you get your moneys worth.
