What signals that a portion size was too large, regardless of feeding frequency?

Answer

Food remains floating or sinking after three minutes

The determining factor for correct portion control is the immediate consumption rate, irrespective of whether feeding occurs once or twice daily. If any portion of the provided food—whether floating at the surface or sinking to the substrate—is still visible and uneaten after the designated consumption window, which is cited as one to three minutes, this is the definitive indicator of overfeeding. Excess food is problematic because it rapidly decomposes, leading to detrimental spikes in water parameters like nitrates and phosphates, severely compromising the water quality environment which is especially stressful for small, aggressive damselfish.

What signals that a portion size was too large, regardless of feeding frequency?
fishcareaquariumfeeddamselfish