As the title says, will a higher amount of water movement cause algae or encourage algae that is already there to grow ? I was just wondering what the thoughts on this were. Im using an external filter for the first time and noticed that there is some gren dust/diatom type algae growing inside the intake/outlet tubes but there isnt any growing inside the tank itself. This got me thinking and Ive always noticed algae growing close to or on the inlets and outlets of filters belonging to me as wells some friends and LFSes. The water flow is also most 'concentrated' near inlets and outlets and within the filter and are kind of like choke points. Is there any explaination for this ?