Sump micro bubbles

OK, I've had it. The microbubbles are driving me crazy. I have a 40g sump that has one divider in the middle. I'm using an Iwaki 100 for return up the show 120 on the floor above. About 12 feet of head.The water comes into the back chamber from the 120 and the 50 gal frag/refugium directly above the sump. I believe the pump drives so much water over the divider that I'm getting a micro bubble fiesta in my tank above. I've tried using filter socks to assist the water in casading over the divider. I've tried turning off the Skimmer.  I put a 90' elbow on my intake, so I only take water from the bottom.  I've also put acrylic 3 sided box around intake so incoming water has to over it before going back down to bottom of sump and into pump.  Hydrologists where are you.  I'm open for ideas and assistance. The helper who helps solves this has a big furry Acro frag awaiting.

Thanks Kirk

Edited by Kahuna

Our skimmer was producing microbubbles and this is how we delt with it.  I don't know if it will help you or not.

We put a foam block in the baffle of our sump.  The water flows down through the block and the microbubbles are removed.

This works great for us.  Maybe you can apply something like this to your setup.

try doing a bigger inlet for the pump. it sounds like you might have an implosion problem. or aleast thats what I call it your 70 should have a 1" thred on the intake I would take it to 1-1/2 or 2". what is it now if it is just 1" there is your main problem. good luck.

Glad you got it fixed.
I was preparing to say that the "physics" of it is that whenever water is moving fast, air bubbles will stay suspended. When the water gets a chance to slow down the air bubbles rise and pop.
Baffles and small openings keep water moving fast.

Is this making sense? Does this describe what you have done?