Help with ASM Skimmer

[SkinnyPete]

just started up my ASM G3 Skimmer today. The pump is pretty quiet but the airtube is making a loud girggle noise. The skimmer is plumbed into a closet so the sound isn't a huge deal, but is this normal? If I block the airtube with my finger, the unit is really quiet. So, it's the only thing making any noise.

Also, is 8 inches of water good for this unit to sit? Should it only be a few days before it really starts skimming?

thanks.

- Skins