I think Soilfloc would ruin a pump, even a trash pump. I had some in a small plastic bucket, and used all of it I could see, dumping the dry residue. I later tried to use the bucket for water to clean floors. The residue clinging to the sides of the bucket, though hardly visible to the eye, clumped up and stuck to the bucket, made the cleaning rag slimy, and I threw the bucket away, as the slime was so difficult to remove. I think my pond is now too clear to use Soilfloc (5 foot visibility). I am waiting for rain to muddy it up, and no wind.
