Getting started
 

My friend said that owning a saltwater aquarium is very difficult and all the fishes will die in a day. Is it that hard?
I have kept a 40 gallon freshwater tank before and a 5 gallon freshwater tank. Should I continue with freshwater or switch to saltwater? If I do what kind of things do I need? If I do get a saltwater aquarium then it would be around 60 gallons. What kind if fishes can I put in there and how many? Note: it would be an artificial reef

Well define artificial reef? You still need live rock no matter what kind of saltwater tank you do. If you are asking if you should do sw, no one can give you a yes or no. You have to want to do it. It is pricey and more work than fw. However the fish and inverts are more colorful. Do a basic search on setting up a fish only with live rock. That will give you a general basis of what you need. If you see that and still want to do it come back here with some more specific questions

Artificial as in live rock with fake corals

Do I need an rodi unit or just ro or none

Ro/di and IMHO you'd be better off with just the LR, the decorations will have to be cleaned frequently and may end up just annoying you

Ok thanks!

Your fish will not all die in a day, if you do it correctly. I'd suggest reading all the stickies on here, they're very helpful.

Do I need a uv filter or skimmer?

Definitely a skimmer. Uv is for fw IMO

Yeah, no uv... Doesn't do any good, just bad. Skimmer you'll need.

Ok thanks!

How many fishes can I put, can I put a tang?

No to small for a tang. You could probably fit 7 small-medium (2-4") fish in there

Not even a yellow tang?

No they need a longer tank. Think at least 6 feet.

Okay, do you live in Toronto? If you do, do you know any good saltwater fish stores?

No, I live in the states

Oh, I really appreciate you helping me start out my FOWLR tank. What is the first fish I should put in?

Hmm you have quite a good number to pick through. Clowns are great but I wouldn't add them first. Do you want reef safe fish in case you want to switch it into a reef or no?

No, corals take to much work and it will probably make my wallet starve.