Could this be Dino's?

[JayLindy]

I'm thinking now I have Dinoflagellates. Tank is about 20 years old with light load of fish and undetectable amounts phos and nitrates. Before putting this stuff under a microscope which I don't have I would like to get an idea of what I'm dealing with. The difference from what I have seen on other posts is that it is more smokey like in appearance without the bubbles. Also snails and crabs are doing just fine.

 

[JayLindy]

The only thing I tried so far was to do siphoning on the rock, coral, and bottom with with two 30% water changes. This has not helped at all. I have also been blasting with a turkey baster hoping it would get removed by the filter pad over the sump but starts reappering within an hour.