I'm going to be putting up a saltwater tank soon, I have a 220g and a 55g empty at the moment this is my first saltwater tank I've had fresh water for years now really want to start a reef tank
+1 if you want a reef tank then use the 55, use the 220 for a fish only tank. Reef tanks you need live rock (1 lb per gal) it adds up when 1 lb of live rock is $6-8. Even doing $6 live rock for the 55 it will equal $330+ tax. And more live rock is better. It's something to think about. 55 lbs of live rock will still make the tank look empty.Smaller is way friendlier on the wallet - I wish I would've went smaller myself but no - had to go monster and spent monster amounts of money and time, so much so It was almost a total hobby killer.
Agree, the larger the more stable, and the dimensions of the 55 could hardly be worse for a reef. Try scaping that 60+ pounds of rock in a 12" wide tank and you'll know what I mean. I would consider a 75 ideal for a newbie tank.It will depend on your budget & time willing to devote to it but do keep in mind that smaller the tank, less forgiving if something goes awry.