I nice nano 240gph or 425gph Koralia should do the trick. I would suggest two, one for each side. They are about $24
Hydor Koralia Nano Circulation Pump/Powerhead
The sale ends tomorrow though. :-( It's 20% off all koralia until the 31st.
Ebay also has some as does amazon.com
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.