which powerhead?

[Maximus13]

I want to get a powerhead for my 40g B, but I'm not sure on which one. I've narrowed it down to the Koralia 240 or 425. they're both about the same size but the 425 has a more powerful motor. I'm just worried that it may be too powerful. but given that it's a big tank, it could work. your recommendations?

 

[Rivercats]

I only use the 240's in my 220g, in a 40 that will be more than enough unless you want alot of current.