When the light is off during the night, in my tank appear hundreds of mollusk-like inhabitants. They look like very little snails with very hard conus-shaped shell. They crowl on the rocks and on the side glass.
My main concern is - are they harmful to my system? How can I reduce their population?
Here they are:
My main concern is - are they harmful to my system? How can I reduce their population?
Here they are: