Detritus

Have some detritus accumulating, mainly on the surface of my gravel, that is apparently to "heavy" to be sucked up by an aquarium vacuum. I don't know what it is; never had it before. Maybe plant detritus?
Anyway, anyone have any ideas on how to suck it out? Even put a small pump on the toilet end of my hose to increase flow. Didn't seem to help.
Thanks for the help.

Could use a pipette or turkey baster to blow it out of place and collect it with the aquarium vac

As for what it is I have no idea. Hopefully, another member will respond