The jump from fw to sw

[reefwars]

I would place the larger power head pointed towards the surface but only enough to ripple it , the small nano koralia isn't very strong that I would have pointed low to keep detritus moving.opposite sides is fine but absolute final placement will be however your rock allows you to provide flow. You need not blast the rock but provide the whole tank with gentle flow and no dead spots.

The idea is to keep the surface moving to pull in oxygen and to keep bio films and oil slicks off the surface and in motion or skimmed out , this is why it's good to get a hang on back skimmer as well

[reefwars]

Also if you paint or vinyl the back panel on the outside black then you won't see your cords and coral colors will stick out more

[dino]

I try to point my power heads in a way that moves the water in a circular motion throughout the tank