Skimmer Setup

[BCWolfen]

I have some questions regarding my skimmer and getting it running right.

I have a used ETSS (older version of the 600) style downdraft skimmer running off my LG 4MDQX-SC. The day I hooked it up it had great bubble production in the reaction chamber and started to produce skimate. Last week it overflowed and I have been having problems dialing it in. So questions.

1) I am drawing water from the input side of my sump by having the pumps intake line submersed in the sump. Should I be building an overflow style box to have it pull water from the surface? The intake side of my sump has lots of bubbles form my overflow and often looks like a skimmer itself with foamy surface.

2) When adjusting the skimmer I have only ever used the valve on the output to adjust the height of the water in the reaction chamber. I currently only have about 1" of water and then the air/water interface. If I go any higher it produces so much wet foam that my 5 gal bucket fills overnight. What exactly does the valve on the air intake adjust (I know I know more or less air injection lol) But what effect does that have on the skimmer. I currently run it wide open.

3) Pump flow. Could I be moving too much water through the skimmer? Should I be closing off the exit valve on the pump a bit to slow the flow down a bit?

I've read as much as I could on wetweb but I could not find a lot that really explains what effects each of the valves would have on the skimmer.

Thanks for the info.