GFO or Bio Pellets - cyano

[Coralgurl]

I have rowaphos (sp) in a sock placed at the first baffle in the sump. I don't have filter socks/holder but was told this would work regardless. I'm concerned I don't have enough flow.

I will check out the products noted and see if I can turn this around. I took this pic last night, all issues are in the front on both sides of the tank, flow seems to blow the sand where the bare spot is.... thanks for the help!!