Reef Octopus Diablo Skimmer overflowing

[pledosophy]

I have a Reef Octopus Diable 160 XS space saver skimmer. The one where the pump is under the skimmer.

Manufactorer recommends at least 12" of water, but even running at 8" now, the cup overfills in a very short time period. Not a thick skim, but more of a very light iced tea look. Mostly water it seems.

Any ideas on why it would still be over flowing? My water level is a good few inches below the minimum water level. When I ran at the minimum it just overflows instantly with clear water.

Thanks in advance for the help.

 

[afm32607]

Does it have an air volute? Have you adjusted the water level lower? (usually means you want to open the valve)