Help making a FOWLR Fluval edge

I have a freshwater Fluval edge that I want to make a saltwater tank. This is will be my first SW tank. I would go bigger but this is all I have. I have a few questions. I want to setup a FOWRL Fluval edge and want to know how. How did you do it? What did you stock? What did you put in the aquaclear 20? Is petco fresh and marine water sand okay? how long did cycling take. How did you deal with evaporation and did you pour in fresh water or salt water? *Was it hard to keep the salinity stable? And what heater did you use? Is this power head okay or too powerful for fish?
It is called a Hydor Koralia Nano 240.
Also, can I use dechlorinated tap water or do I have to use distilled water? I'm in NYC btw.
Any other suggestions or tips?*