When to upgrade skimmer?

[spedly]

That's all very good information. Thank you! I've got very good circulation in the display and my nitrates/phosphates are consistently at 0 so I guess I'm good for a while.

Truth be told I think I'm trying to validate the purchase if a new skimmer. This Tunze seems to work well. It's the only skimmer I've owned that actually worked so I can't compare it to anything. My only complaint is that it's a little louder than I was expecting.