[Birdlady]

With the substrate, you said it is aragonite. Is it crushed coral, or more like sand? If it is like sand, with the smaller grains, you will eventually jam up your powerheads as the sand will likely get sucked under the plate and up the tube. Since you have just started, I would get rid of the UG plate, and get strainers for the powerheads instead. JMHO...

5 or 6 fish in a 50 gallon is not what I would call 'light' on the fish load. The rating is different for saltwater fish than for freshwater. It can be done...you will be fine, but like APC mentioned, you should have a good protein skimmer.

You should be fine with most soft corals and LPS corals...I am not sure about clams and SPS corals with the PC lights. Some folks have been OK, and some have problems....

The wet / dry and UGF was a good setup for an eel, as they are heavy producers of waste....with a reef tank, you may want to be set up a little different. I would toss all the bioballs before you have a good bacterial population on them, which makes removing them a bit more tricky. Just use the W/D as a 'sump' in which to put all your filtration, heaters, etc ...

Hope this helps a bit and keep the questions coming!

And remember, there is always more than one way to skin a cat! Research and do what you can live with!