Algae on sand

[Adam Sklar]

My phos is pretty low and in check. But lately I always have algae on my sand. I have a new clean up crew also. Could it be not enough flow?

 

[Coralreefer1]

Yes it can be that your water flow is insufficient. Moreover, you probably have elevated nitrate levels too. Water changes and minimizing feeding will help. It could also be your lighting. Duration, intensity, spectrum(kelvin) color of bulbs and possibly time to replace your light bulbs.