I can't answer your specific question about the air pumps, but I can offer the suggestion of using powerheads instead of air pumps and stones. I much prefer that configuration. It's typically less maintenance than an air pump/stone setup, though you do still have to clean the sponge. As a benefit of using the powerhead, it's definitely much quieter and you can use the outflow to help with the circulation in the tank. I've personally never had a powerhead fail, though I'm sure it happens, but I have had plenty of air pumps die.