I bought a Coralife 220 which can push @ least 650 gph...my tank is 55 gal. I plan on putting in a refugium with the skimmer in the refugium. My question is do I need an overflow from the tank that will @ least do 650 gph or not??? I have an overflow that does 300 gph...will this work??? & same thing with the return pump...do I need 1 that will push @ least 650 back to the tank??? Thanx...

nope. Your overflow will do fine. I would go with a mag drive 3 as the return and your skimmer is with the sump so it will just re skim the water which is good. Those skimmers are HUGE just make sure you baffle the skimmer before the refugium. That way your refugium doesnt get a lot of detritus. If possible I would have jst a sump and a refugium seperate...That would be best. then you wouldnt have to baffle a tank. maybe a ten gallon refugium piped to a 15 gallon sump.