I recently got a great deal(130.00 for tank,stand, hood, and a sump) on a used 75 gallon old reef tank. Now it would be great if I wanted to do saltwater since its predrilled and came with a sump but I want fresh water. So any advice on cleaning it out? Also any advice on plugging up the predrilled holes. Thinking I might just be able to cap em with some plumbing supplies.