my 50 gal i had 2 koralia 1400`s and i think it was just enough , for a 120 i would go for like 6000 gph .

Mag 7 as in this one is only 700 GPH. Is that the pump you were thinking of ?

Nope, the hydor koralia magnum 7 is this one
http://www.bulkreefsupply.com/store/...2-700-gph.html

That makes more sense :smile:

My 120 is using quiet one 4000 high head for return, and 2vortech mp40s

Wow, so that's roughly 10k gph flow?

Im seeing there's lots of variation in what people use, I'll have to find a sweet spot between 6k and 10k depending on rock work and coral placement.