i would say that it is.
diatoms wont be snotty. there is a difference between algaes. the more common of them that are hair like, there is breopsis that is hairy, but has fern like hairs, there is green hair algae, which is a really fine hair that would remind you of a makup brush. then there is dinos. dinos have a couple different versions. i have one of them, or at least i think i do, that has a hair like structure, but is different. hard to explain, but the more common type of dino, which you probably have, is the type that is snotty. if you were to use a turkey baster, it would probably blow off the sand fairly easy but holds a form that is more like a slime, snot, or whatever other grossness you would want to compare it to.
also, dinos will usually have an air bubble that is attached to it. that is generally a pretty common thing to see with dinos
