To me personally, overstocking is when you have a (or a few...) big fish in a tank that is far too small for it.
Also, if that small tank isn't well filtered.
So, its really all of the above. I think the hard thing is the fact that there is no clear definition of "over stocked". Its too subjective.
Also, if that small tank isn't well filtered.
So, its really all of the above. I think the hard thing is the fact that there is no clear definition of "over stocked". Its too subjective.