Choosing between a Koralia 4 and a Nanostream 6045

[Canadian]

Don't even think about buying the 6045 if you own a Dremel and have even the slightest amount of patience. If you mod the shroud on a 6025 you'll get the same 1189 GPH out of the 6025 that you will out of a 6045. The only difference between these two (the 6025 and 6045) is that the shroud on the 6025 restricts the flow - the "motor" for the 6025 and 6045 is the same. Roger has admitted this on RC. The restriction of the shroud on the 6025 was done so that there was a Nano Stream that could be used on small tanks.