Wow, this is so great.... so I picked up an AquaClear Powerhead for my 50G and bought the Quick Filter Powerhead Attachment that Diana and others have recommended. I had to buy it off Amazon b/c they don't carry it in my local pet shops. Best thing though is that you can order replacement cartridges to be shipped to you automatically by Amazon. Such a huge convenience! So I'll be getting a box of two replacements every two months don't even have to worry about remembering it get them. Man, fish-keeping has changed A LOT in the last 10+ years I've been out of the hobby.