CPR Overflow CS50

[daddy01]

Hi,
Just got a min refugium up and running on my 30G reef, using a 10G tank underneath (one flood so far), but I find it noisy and quite a bit of bubbles. Has any one any recommends to quiet the thing. The noise (most of it) is from the output into main tank as is the bubbles. I submerged the output which did make it quieter but with power outage it syphons main tank into 10G tank ie the flood.
Any other recommendations. I have hearing impairment but my wife can hear a pin drop blocks away.
Jim