hi all, i love marine tanks and have just set up my new 3 ft tank recently about 3 months ago. Actually have started about 1 year ago but its also not sucessfully and most of the fishes / corals die after few weeks to few months after i bought them. So was hoping to find out, what are the essential for keeping a marine tanks ? I got a Protein Skimmer, Filter system , no chiller yet. Thanks for any advice.