in a 30 gallon you can get away with just 30-50 lbs of liverock that filter along with a few powerheads and if you do alot of water changes you can get by without a protien skimmer
in a 30 gallon you can get away with just 30-50 lbs of liverock that filter along with a few powerheads and if you do alot of water changes you can get by without a protien skimmer
If the Magnum came with the white micron filter, then it's useful for polishing the water, otherwise, it's not terribly useful in a saltwater tank. As others said, the live rock and powerfilters will give you a wonderful, natural filtration system.
I used a HOT Magnum on my 29 but eventually took it off of there because it was so incredibly loud and maintenance was very annoying. I tried using it on my FW tanks, but had the same problem with noise.
I used a normal Magnum and took it off because it was a pain to maintain and the flow from it dropped drastically quickly after cleaning. Haven't had any problems without it and the water is still clear...