This could be the problem. When I try to siphon the bottom, with the water siphon kit, the amount of gunk stirred
up into the water is its own cloud, and it looks primarily like uneaten food particles.
Is there a fish that specializes in eating bottom particles? The sucker fish seems useless in that regard, besides being super ugly and really hard to catch (it's the fastest and squirmiest of the fishes we have) when moving things around.