Bak Pak 2r+ question

I just bought a Bak Pak 2r+ and have a question about how it should be set up. There is an airline coming off of my powerhead. should i have this airline submerged(less bubbles) or out of the water (lots of bubbles). Im sure this may sound like a silly question, but theres only one way to learn, right???
Thank you so much

 

In addition to my previous question... my skimmer did not come with an overflow box. is this necessary? if so, where does the overflow come from, the skimmate cup??
thank you for your help

 

You want the airline out of the water. You don't really need the overflow box but with one you'll be able to take the slime off the surface of the tank water. This place sells Bak Pak accessories: Ameka Aquatics - Product Info

 

Great! Thank you for being so helpful!
In addition to my previous question, i am trying to figure out how to decrease the flow, as my skimmate cup is filling up almost hourly. there is two knobs on the side of my powerhead, one is the airline and the other comes out of and goes back into the powerhead. i have rotated them and it seems to have decreased the flow. is this the correct way of adjusting the flow? if anyone has any input i would greatly appreciate it.

 

Raise the collection cup up by moving the band further down on the cup. That will give you a drier skimmate. You can also go on the CPR website & get the directions.