Starting my first coral tank. 20 Gal. Looking for flow ideas. Was looking at Gyre 130 or 150 if I can acquire one (they seem to be hard to come by). If not, possibly a 230. Seem to be the only ones that will fit in the tank. Are they overkill? Can they be run on less than 100% and perform well in a small tank? Any recommendations for different styles or types? Thanks.