What pump would you use?

[Delphinus]

I don't really think it's going to make a big pile of difference Jonathan. Try it both ways maybe and see. Your LG is not a pressure rated pump but that doesn't mean it can't handle a little bit of head pressure.

That said, personally I'd probably take the LG4 for the closed loop, just since I think the Mak will handle the number of bends in your return just a tiny bit better. But I don't really anticipate that it's going to be a really significant difference.

I think you'll probably find given enough time that you will be disappointed with just 4 MJ12's on a wavemaker, in fact it's almost negligible for flow. Remember I have 4 MJ12's in my 75g, so if you want to see just how much flow that this is NOT, come on over and look..