new to marine

okay, I will start out by saying I am experienced in freshwater but marine is a whole new ball park!
My fifty gallon is completely empty, and my planned setup is 3 15lb bags of carib sea argonite, and i bag of crushed coral, 50-75 lbs live rock, an aquac remora pro protein skimmer, and really expensive lighting *sigh*(I am shooting for reef tank).
My confusion lies in 2 things, first I dont know what kind of current devices to use or how many and I am confused about refugiums. my tank is not pre-drilled and if I get a tidepool S.O.S. skimmer(overflow) could I rig it up (simply) to the ten gallon tank I have as a refugium? I want to do it as simple yet effective as posible. I have the concept of a refugium down but dont understand the setup.
two last things is are there any problems with not having media filtering? and when an ro\di filter says 50 gpd, does that mean it would take a day to fill my 50 gallon tank?

[Birdlady]

It will probably take closer to 2-3 days to fill depending if you are comfortable letting it run overnight. gpd = 24 hours...but I found my 75 gpd took 2 days to fill my 58 gal + 15 gal in sump ...maybe a little under 2 days...

Welcome to 3 Reef! I am a revived newbie (had a tank 6 years ago, but so many things have changed!!!) Everyone here has been extremely helpful!!!!!!