Hello everyone,
My 180G build is nearing completion. The tank is full and
cycling 
has begun. My tank is a standard 180G (72" x 24" x 24"). I have 4 - Tunze 6101's (Old school design) and a 7095 Multi-Controller. I was wondering what would be the best locations for my powerheads. There are a couple options and not sure what is best. My rockwork does not touch the back of the tank at all. I have attached a picture of the aquascaping. I was thinking to set them up using one of the following options:
a) 2 powerheads on each side of the tank. 1 flowing behind the rock and one flowing in front of the rock.
b) 1 powerhead on each side flowing in front of the rock and 2 powerheads on the back of the tank flowing towards the front pane.
c) All 4 powerheads on the back flowing towards the front pane.
Any opinions would be greatly appreciated!