Welcome to PBF SharpestJim,

I'm not a pro but I think the HP100LL compressor might not be the best choice. From what I've read, its max operating pressure is 4.3 psig, so about 8 feet depth. What that means is it will not be able to deliver airflow at your desired 12 feet. Maybe someone that has more experience with diaphragm pumps will chime in. Have you looked into small vane pumps?

Again, welcome to PBF!

Bill D.

[Linked Image]
Be Brave Enough to Suck at Something New!