Black Matter at Base of Frogspawn - Pics Attached

[OceanLab4]

Ive had this frogspawn between 4 and 5 years, and it's done great. While looking over my tank today, I noticed some black matter at the base. It looks like I could take a turkey batter and blow the particles away, but wondered if I should be concerned? Any input is appreciated. Tried to attached video but keep getting security error

 

[DSC reef]

Looks like detritus and algae buildup

 

[OceanLab4]

I can live with that. Thank you! I took a powerhead throughout the tank last weekend and vacuumed it well. Looks like another round might be needed.

 

[DSC reef]

There's nice babies sprouting in those pics, looks healthy.

 

[OceanLab4]

Thanks! I was able to remove the black stuff.
All is good now :)