Which Seachem impulse?

[BullyBee]

I was just wondering if it matters if I use a 600gph return pump with a 3/4” Return pipe for a 40g breeder display tank or if that would be too much?

I can get a 600gph Seachem impulse, or a 400gph Seachem impulse.

 

[Daniel@R2R Verified Admin]

I'd go bigger rather than smaller