I was a complete newbie when I started on my 30 gallon (with a 15 gallon sump) a few months ago... (so I guess I am still quite a newbie now, compare to everyone else on this board
). I have a total water volumn of around 40 gallons and find that it is quite easy to maintain, and I am able to keep quite a stable environment. It helps that I keep my fish load relatively light, feed lightly and have a nice refugium packed with chaetomorpha.
-Richer