Recommended Settings for Four (4) Tunze Pumps

Hi and thanks for reading my Post. I am trying to determine the best Profilux settings for my tank. I have a total of four Tunze 6105's (one in each corner of the tank) but cannot seem to find any recommended setting for four pumps. Lots for 2 and some for 3 but none for 4! I am looking for advice on the right Profilux setting and also some suggestions on where best to place the pumps as maybe one in each corner is not correct.

My tank is 6ft x 2"5 x 2"5 with the overflow box at one end protruding in the middle about 30 centimetres (10")

I'd appreciate if anyone could provided some suggestions as I am really lost and having a hard time trying to get things right to keep my corals happy.