Powerhead positions in Peninsula Tank

[psumms]

Hi all, I have a 5 1/4 ft peninsula tank (Red Sea Peninsula 650), made a quick layout sketch below... Currently running three MP40's in three corners but have one corner where there is little flow and a build-up of waste. I'm unable to located an MP40 there as there is no access outside of the tank due to it being against a brick wall. I run my MP40's through an APEX WXM controller. Any suggestions for where to position another pump (and point flow) and ideas for a pump type. Another MP40 pointing inwards doesn't seem a good idea.

 

[reef lover]

If you get an adjustable pump like a tunze or jaebo you can put one in this area up high and aim down and toward that corner to pusj the debris out.
Very limited with options for another mp.