I want to create a decent amount of circulation and i currently have a mag 7 on the return. What would be a better choice two k4's or k3's? I dont want to over do it or under? any mix match would work as well...

i would think that you should have somewhere between 1500 to 2000 gph of flow. with multiple powerheads so its not just a constant one way flow.

so you suggest one 3 and one 4 or what?

Get 4's. I had 2 K3's on a 75 and it seemed like a lot, but it's really not.

I have a 55 with 2xK3 and 1xK4 plus a large return pump - and my tank is fine.

Someone will clerify soon I bet.

My opinion. What will be in the tank? 2 K3's is good if you have alot of softies. 2 K4's if you choose alot of SPS.

Money always rules this too.

Maybe 4 controlable K3's and a wave maker. That's a good wish list.

someone told me to not count on your return pump for flow...
I have a mag 7 on my 65, I really should have a mag 5 with the way my set it up is.
I currently have about 35x the turn over rate but I use one of the power heads just to keep the surface from being "still"

also the coralvues, I know that isnt how you spell it, tend to be cheaper... I have a 1350pgh coralvue in my 65 and it was 40 bucks...the koralia 4 which is 1200 Gph is 50 I believe.

I picked up two k4's for 34 a piece last weekend at Aqauriums unlimited so i think that will do the trick...thanks for the input tho