Id this, flatworms or red bug damage

[Rod Buehler]

A guess by looking at that picture, and where the damage is, I would guess that its a flow issue/detritus build up that will allow the amphipods to play/build a home in that area. But that is a guess from that picture. Cant you get a closer more detailed shot of the affected area?

 

[skunkmere]

yes, ill try tonight. this is the same issue from last fall, i posted on here but now i got a better camera, so ill get a nice shot of it.

thanks