So I got my powerheads today, and I'm having trouble setting them up.

It says it should be fully submersed, but the venturi thingamabobber only works when the top of the powerhead is just above the water line. So should I fully submerse the powerhead, or should the top of it be just above the water line? The picture on the front shows it fully submersed, but with the bubbles coming out of it... I'm using it for aeration, and unless the pump is out of the water a little, it creates almost no surface disturbance. I guess I could get some tubing and run that off the output up to the surface, but I'm wondering if I'm just using the powerhead wrong.

Any help would be appreciated.

yup, you're right, the venturi thingumee needs to be above the water line. -if you want to have your powerhead at a lower level and you have an attachment, sure you can add a piece of hosing up to the surface, just be careful that it's positioned so it doesn't overhang the tank, I had a piece of tubing on a venturiwhatsit and for some reason, (power out, slowed speed of pwerhead due clogged intake ) water tracked back up the tube (maybe by capillary effect) and started siphoning water out of the tank! so make sure the end of the tube is located over the tank or at least well above the water line.

It has a venturi tubing piece that goes above the water line, the problem is that it doesn't actually do anything unless the top of the actual pump is also above the water line. If I have the pump low enough for the water to be just barely covering it, even with the deflector pointing towards the surface it makes almost no surface agitation at all.

I'm wondering if I just got too weak a powerhead, which is sad because I bought two of them hoping to be able to get rid of the really annoying and too weak air pumps.

I may end up getting some tubing to come off the output of the pump and somehow rig it so that it is directed over the surface of the water, and hopefully do that instead of using the rinky-dink output thing that they have going on.