I have tried to research both as much as I could. The pros of a submersible sump pump are that it is sealed and cooled by the water that it sits in, so it may not be as susceptible to overheating. However, I have also read reviews (one in which the person literally bought a new one and the motor seal leaked the first time he tried the pump) that stated that these generally fail within 2-3 years on average. Supposedly the submersibles pump more water. The pedestal sump pumps...the motor is air-cooled and not submerged in water constantly, of course. I have read that these have been known to last up to 15-30 years in cases of really good pumps. They are supposed to be protected from thermal overload. They are more noisy, however. Why are these becoming less common and the seemingly less durable submersible pump are becoming more common and more expensive than the submersibles?

I have a aerobic mound septic system and it seems as if the air pump went out and the alarm never went off letting me know. I have three chambers in this system (1st collection tank, 2nd treatment tank and 3rd pump tank). I noticed a problem due to some liquid around the lid of the third pump tank. This led me to check the air pump and yes it died. I have ordered a new air pump. Should I just have all three tanks cleaned out and let the system start over with the new pump? Thanks.