Bought 'used tank'... advice?

[dgbnyc]

I have a 50 cal tank with a large wet/dry, UV filter , back pack Skimmer & hood that has one 48" UV lamp.
There were a few fish in it but they died! The tank Ammonia and Nitrate were high and were not going lower for around three or four weeks.
I want to set this tank up right.
What do you suggest?
The skimmer seems loud and causes the water to become cloudy when I use it (suggestions on this one?).
There is some brown algae and a bit of green growing.
The tank (got it used) came with some rocks that were live at one time but look very dull now.
Would you start my tank by buying new & placing LR in the tank then adding fish?
How about these 'clean up packages' I see for sale online. Sanils, shrimp & crabs... does the tank need to cycle fully before I add any of them in?
Your advice is much appreciated!
Thanks,
David
<img src="graemlins//urrr.gif" border="0" alt="[urrr]" />

 

[fshhub]

i would fully cycle before adding anythign, even fish
was this a marine aquarium when you bought it, and the lr was it definitely live rock? if it was live rock, there should not have been a big cycle, if not i owuld definitely get new lr, after i contacted the old owner to find out what they had kept in it and if they ever had to treat for diseases, and if so what meds did they use, if htey ever used copper, good luck with any lr and inverts, so i'd start there