I have the very same set up. The instructions for the Milwaukee say to use 10psi, so that's what I used.
If you start at a low rate then you can move up slowly, I began at 1 bubble every 6 seconds (10bpm) and then as the CO2 in the fresh tap water left the tank, I increased the bubble rate to get the pH where I wanted it. I'm at 17 bpm now -- though that will not mean anything to you since my tanks and water are certainly different.
Have you secured the tank properly? I made a velcro strap to tie the unit to the inside of the cabinet.
Oh, that reminds me, I just added glass tops to the tank to fix a moisture problem in the light fixture fans... I need to recheck the CO2 level, that might have increased it.