Oedogonium is unbranched filementous form with cap cells and oogonia ( these are identification marks for Oedogonium)
Further Coleocheate is discoid structure with reduced erect system and I don't know whether it is Coleochete or not
I strongly believe it may be cluster of algal forms which form the bloom. so better to isolate the individual filaments and examine under the microscope.