Can Diatoms be stringy like dinos?

[Animal-Chin]

My new tank is under attack. I had the classic diatom bloom after the cycle, it cleared up other than on the sand bed. Then, the stuff on the sand started to look snotty/stringy like dinoflagellates and I thought oh no. But I've had dinos before and this seems a bit different.

Firstly, the strings don't have air bubbles which seems weird. I remember my old dinos all having air bubbles.

Secondly, the glass and rock are also covered in powder that can be blown off with a turkey baster, this seems classic diatom rather than dinos?

Third my snails/crabs are all fine. None of them have died which I under stand is common with dinos.

Other than a microscope, which I don't have, does anyone have a sure fire way to tell what I'm dealing with her? Anyone have experience with stringy diatoms?

Thanks all, Gord.