@katbyter Its been a long time since I had an aquarium, and I never had one of them, but the Mystery snail or Nerite snail are two good choices for algae eaters. We always opted for one of the algae eating fish. I don’t remember the exact species, but my kid always referred to as the side-sucker.
Oyster - but I would need to have the dust bin compress the contents under extreme pressure to turn dust into diamonds. Imagine an oyster that makes diamonds! It would confuse schoolchildren. They’d be expecting pearls.