Wastewater Treatment Plant Service

• How much should my replacement aerator cost?
  
• How often should my Jet wastewater treatment plant be serviced?
  
• Can I service my Jet wastewater treatment plant on my own?
  
• The pre-treatment cover to my Jet system does not have a riser and the cover is buried.
  
• Our home has an older model Jet Inc. aerator. The "filter warning light" has come on. What should we do? Is there another pump in that section of our aerator system?