Eric, just a couple of notes.
1. I use the HiBlow air pumps, made in Japan, obvious quality, but noisy enough to be in a closet or another room. I bought from Pets and Ponds.
2. I also use a Fairchild regulator and a blood pressure gauge, allowing me to tune the sound towards warm (low pressure, about 9 mm of Hg) or precise (high pressure about 30mm Hg). Note that 760 mm Hg is 1 atmosphere or 15 psi, so 30 mm Hg is 0.6 psi.
Welcome to the club!