White webbing-like substance in tank

[Frogger]

I have vermetid snails in my tanks there are thousands of them every inch of may tank is covered with them. Each of my snails have a half a dozen or more on them. They have never produced webbing that has extended more than a few inches from their shells and never anywhere near that dense. Also the webbing is only visible when it traps food. His rock appears to be free of their shells. I can't see any on his rocks. So unless this is a different variety that is hiding in the back and produces enormous amounts of webbing I vote that it is not vermetid.