Euro Reef

[Jaws]

So I've had my Euro Reef set up for a couple of weeks now and am waiting for it to settle in. It hasn't really started pulling any stuff out of the water yet which is kind of weird. I'm just wondering if anyone else has any experience with these skimmers and might be able to offer some suggestions to get it working at it's best. It's a CS8-3+. It has two sedra pumps, that each have their own airline with a shutoff valve. Should the shutoff valve be open all the way? The only other valve is the main gate valve which is turned almost half way off right now in order to get the bubbles to even reach the top of the bubble chamber. That doesn't sound right to me. Any help would be appreciated. Thanks.