So I thought it was poop but now I think it may be something else.. On the one it now looks like the stringy stuff is on the rock its attached to and figured ide ask the pros here! Thank you all in advance!
Could also be dinos possibly. Mine looked like that. What are your no3/po4 levels?
If you don't have a microscope you can do a test to find out. Collect some of it with tank water and put it in a container with lid. Shake it up well and then strain it through a paper towel into another container. If after an hour or 2 it regroups, it's dinos.