Direct or indirect flow?

[Crackem]

I have a mixed reef with mostly sps, but also have a nice pink tip elegance on the bottom and a frogspawn in the middle. My tank is a 72 bowfront and I'm using 2 tunze 6105's which are rated up to a 180 gallon tank, but I'm only using the 12v jumper instead of the 18v or 24v that came with the pumps.

I've tried aiming the powerheads in a few different positions to make the lps happy and now I have them mid way down the sides of the tank with both aiming up.

My lps are happy but I'm wondering if this is causing cyano to grow on the live rock on most of my rocks that are up high.

My po4 is usually 0.06 because my sand and rocks were never properly cured when I moved my tank from one apt to where its at now.

Should I aim the powerheads directly across the tank instead of towards the top?

Or

Should I try the 18v jumper and increase the amount of flow in the tank?

Thank you for any input

 

[epicurus84]

Yes, acros the tank, it should hit the top anyhow. If not place it higher in the tank. Tunze also has some wider flow nozzles if you have the older tunze 6105 it's quite narrow. The wider isn't as agressive.