I've used a lot of the C D battery styles. Some last a year, some more than a year. Don't know the hours used.
This one has lasted 4 years. Marine Metal Products Bubble Box™ Air Pump | Academy
This one lasted 3 years. Marine Metal Products Quiet Bubbles™ Bubble Box™ Air Pump | Academy
I picked up 2 Laker bubblers at $13.95 for back ups. Laker Piston Pump Aerator AE1 Lot Of 2** | eBay