Yes,
Another Trick Question.
Under Skimming
For Example:
Your return pump is rated for 1500 g/h and your Skimmer is only rated for 500 g/h.
More Nutrients are going back into your tank than are being filtered.
or
Dirty Water.
Over Skimming
For Example:
Your return pump is rated for 500 g/h and your Skimmer is only rated for 1500 g/h.
Less Nutrients are going back into your tank,
Better / More Mechanical Filtration.
or
Cleaner Water.