I have a 120g Mega-Flow tank drilled for 2 overflows and rated at 1200gph. I plan on using a sump/refugium as well. I have read that your return pump should only push 5X +/- your tank volume. Am I supposed to get a return pump based on 5X tank volume and add other devices for additional flow or get a return pump that will get me closer to the 1200gph rating? I would like to keep the tank as free from additional hardware as possible.