No, it isn't. It's obviously sand/dirt. I am sorry that I guessed at that. Experience has taught me on this forum that that issue will be algae 95 times out of 100 but I guessed nevertheless. I would not pursue "algae" as your problem.....it is sand.
So, if this sand suddenly appeared a weeks or so ago, can you recall any changes you made to the pool at that time? It looks too coarse to be blown in.
Curious.....why are you calling it "silt". Silt is powdery and close to mud........your pics look like clean washed sand.