I am going to set up a 55 gallon reef tank and will have a skimmer and live
rock. I was considering a refugium, but dont want to hassle with it really.

Is a refugium really necessary? If I don't go with a refugium, but do use a
skimmer and live rock, is there anything else someone would recommend?

And if a refugium is very highly recommended, I have a 15 gallon tall
tank..is there a kit to turn this into a refugium?