For a while I ran my water to the grow bed directly into my media guard around my siphon. Someone thought I might be bored and playing around too much and thought it might be a risk to the fish, so I stopped doing it.
No doubt sound advice.
But I suspect it worked fine, because any solids that didnt stick, become free to move around giving them another chance to stick somewhere else.
I found the water was still crystal clear, in spite of returning some water back to the fish tank without having put it through the media.
I also find that my scoria grow bed manages to filter out it's own dust within a few minutes these days. If I dig the bed over like I did when searching for worms, the water gets a bit clouded for only a very short while. The particles floating around in the water always find a place to settle down, even when they are tiny.
For some reason it hadn't occurred to me that it's because of all the chances they get.
It's inevitable that they get stuck.
They only have to get stuck once.