I think the Tunze nano will kick it's butt 100 times over (LOL). Even my little maxijets seemed to produce a bit more flow for the tank and they aren't rated flow wise quite as high as the koralia. The one I tried out was rated at 400 gph and maybe it is just because of the wide gentle flow it distributes, but personally, I chose not to use it. This is in no way grounds for you to decide on using one or not though. Just thought I'd throw out my personal experience and views on them. I'd wait to get a bit more feedback from others first before making a decision as others may have had some success with them and love them! I have used the Tunze nano before and I must say, I love them!
I have a 29, with a Koralia 1, rated at 400 gph. I recently purchased a Koralia nano 240 to get more flow towards dead spot at the back of the tank. In comparison to the two, the 400gph has worked wonderfully for me, has a wide spread amount of current vs. the nano, which it seems directs the current more pinpoint, less widespread.
The nano is only slightly smaller than the 1 and the price is about the same. The Koralia circ pumps are nice and quiet, you can't go wrong there. Perhaps buy just one and see how you like the flow and if it's not enough then add another?
Hope that helped a bit
In some cases, I like the widespread gentler flow if directing specifically over corals, but in other cases, I love the pin point flow. I tend to use pin point flow to direct flow at the tank walls where another powerhead (or other source of flow) would colide with it creating some crazy random flow that goes everywhere! I am a flow junkie though so what some might think is enough flow is usually far from enough for me so I tend to never push my flow opinions on people. I once had about 4,000 gph of flow in a small 38 gal cube!
