If I understood your original plan, it was to run the output of the skimmer to one of the elbows meant to be a skimmer intake. Unless you raised the skimmer immensely, even if the pump was strong enough you'd be spewing water out of the top of the skimmer.
That looks to be a Coralife skimmer. I have the 65 model in use as a HOB
. I can't quite make it out, but I imagine that your return pump is in the same compartment as the skimmer. I would get a foam prefilter block to put on the skimmer output which will cut down on the bubbles, and another (if you can) for the return pump intake. I think this will be the simplest solution to your problem. Mine does make some microbubbles as a HOB
, particularly after a good cleaning, but nothing that's intolerable. However, my output runs through a little box with foam blocks in it to diffuse the microbubbles.
I can't tell if your skimmer output is below the waterline of your sump or above. I think if it is just above with the foam filter it might work best. In any case, the foam block on the output is where'd I start to see what happened and you can alter the depth of the output to tweak it.