steel3470,
Let me encourage you to not use the penguin power filters if this is for the 50 gal salt tank you are starting up. I have two penguins on my 75 gal salt...and their great filters...but hang-on powerfilters are not the best choice for salt. They disturb the surface of the water in such a way that it jumps up and splashes on your lighting/glass cover/hood, which leaves tuff to remove salt deposits on them...damaging your lights and inhibiting the light penetration through your glass. Also, canister filters offer way better filtration and are a better option... I'm about to switch over to a canister filter like the Rena Filstar or Fluval. Take it from somebody who learned the hard way...a few extra bucks for the canister filter is the way to go. Hope that helps...
Zach