I would go with 1 wp25 and see how you like the flow, if you want you could add a 2nd, but you should not need it. On my 40 bowfront with the pump around 1/3 of they way from the top I get a great wave on W1, S2, and the dial right in the middle. I would expect that you could get the same with a single wp25, given that the pump is only running at 75% on mine.



