Need Help with Dino ID. what type are these and do they go into the water so I can zap with UV?

[JRS-REEF]

Need Help with Dino ID. As far as movement they kind of speed around and do not spin in place like some do. What type are these and do they go into the water so I can zap with UV? Any other suggestions are welcomed.

 

[taricha]

I think this is large-cell amphidinium, not a water-going type.
can we get a pic of the brown stuff in the tank for some more context?

 

[JRS-REEF]

Here You go!

 

[taricha]

Yes, that could be the large cell amphidinium. Looks pretty stuck to substrate.