Going as natural as possible is the best method of filtering a SW
As the others have said 1.5-2lbs of LR
per gallon or 75-100lbs of rock for your tank. All of that rock does not have to be "Live" to start with, you can get base rock (much cheaper) and seed the tank with a few pieces of LR
. The LR
will constitute the bulk of your filtration through the beneficial bacteria that will grow on the surfaces.
What I do for filtering my system is lots of LR
, a large refugium and a large skimmer. Your refugium does not have to be anything special. You can use a plastic tote from walmart or you can spend the money and buy a nice acrylic one. I use a 20g tall tank as my fuge.
To keep SPS
corals in a 50g tank you will probably need to go with 6-8x54w T5HO or a combination of MH
and T5, VHO
to get enough light to support them.
When you get things started you will need excellent flow in your tank to keep SPS
corals as well. You will want strong and random flow.