skimmer question

[20114]

I've got a deltec mce300. This is supposed to be a good skimmer, but why do I need to clean it out everyday to get more than 1" of scum collection? Initially I thought it was b/c I only have 3 fishes, but now I'm thinking maybe there something I'm not tweaking properly. Anyone have any ideas? I have it hanging on my tank with the air nozzle fully opened. Thx!