How high do you fill your tank?

I try to balance the needs of my HOB filter, the uneven floor that gives me a half-inch difference from left to right on my 48" tank, the surface wash at the output of my canister filter, the spray from my bubbler, and the desire not to get splashed in the face by hungry goldies.

All in all, I usually run mine about an inch down from the trim.
 
i sometimes have it low and other times have it really high, i think it should all depend on the what fish you have in the tank and how many plants you have.
 
My BioCube I fill to the very top, or a little lower if I make sure to dump some ewater in the pump return, otherwise it ends up sucking air.

My 5 gal has a brigg, so I leave it about an inch below. My 10 gallon I leave about an inch below, too, because it's on a lower stand and that way I can see the top of the water when I'm standing. It has a Tetra Whisper filter, so even with the waterfall there's not much surface agitation, so I added an airstone.
 
As far as I can without overflowing. The bare minimum is so you can't see the water level below the lid - I like the look of a solid block of water, and pretend there's no air in there :)
 
this is interesting....for 8 years i have had this tank i have always kept it at the same level and now i realized that a bit higher might in fact be better!!!!

now i hope that when i get home i dont have a bunch of dead fish due to the difference in surface agitation and co2 injection.
 
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