How much power is too much?

[JWFokker]

I'm fairly well versed with traditional American style 3/8"-1/2" watercooling, but I'm trying to get into more German style systems. Now I'm stuck on pump selection. With smaller ID tubing, using a low flow block like a Nexxos, how powerful of a pump do you really need? I've been looking at the Danner (Supreme) Mag 2. It pushes 250gph and has 7' of head. Is this too powerful? I don't want to get into any trouble with laminar flow. At $35 (since I can't get the C-Systems pump any time soon), it's a good deal to me. What's the general concensus on pump power in German style loops?

[Starbuck3733T]

With a block like the nexxxos, too much pressure won't be an issue. I don't think 250GPM through that would ever get you laminar flow.