Just spent this weekend getting the water flow right in my Mbuna tank. Seems that the tank had two dead spots in it and waste was collecting in these areas (not to mention the caves were filling up too) I already had a Koralia Nano (400 gph) in there at the surface pointing down to help, but it wasn't enough. I purchased a Sicce Voyager 2 ( http://sicceus.com/voyager.html ) and proceeded to dismantle and rebuild the lace rock structure. The pump was mounted against the side glass (magnet mount, very strong and secure) at the back/bottom right side and I built a pvc 1/2" frame to go around it. I already had a pretty big frame that I left along in the center of the tank (you can see the brown algae all over the untouched rock) and built caves to go around the frame that covered the pump. Making sure to leave the entire back run open. Same thing on the left side but no pump needed there. I pointed the 800 gph pump straight down the back of the tank to flow water right through where the Spray bar from the Eheim and the Koralia could not touch. This creates a circular motion of water from top left to botom right and back. I have NO waste build up now while maintaining lots of caves and hidey holes. The water clarity has been awesome ever since too. The Voyager pump is a VERY nice pump and would buy one of these again over the Koralia. Not that there is a prob with the K, just that the Sicce is a much better pump. Pics below
End result of the new structure:
End result of the new structure:
