Jebao WP10 or Koralia (240gph) on nano?

[daplatapus]

I also have a WP25 in my 18" X 18" X 18" cube. On it's lowest setting, I have no doubt you can set it up to not create a wave. I have mine 2/3 of the way down pointing up and on it's middle setting it gets about 1/2"-3/4" wave going. But even then you can slow the pulse so it just breaks the surface and doesn't actually create a wave.
I'd recommend going with a WP25.