The Mag 350 says it does 100 gph, so does that mean it really does about 50 gph? I understand about the bells and whistles thing. lol I see some little tanks on here with lots of fish (atleast 20-30) in them and I wish I knew what their filtration was because we plan on the 120g and don't want to under do it. I'm still learning, please bare with me...