From time to time (rarely) beads require replacement. Especially true if you accidentally let beads out of your sludge valve on the bottom. These are the same beads as specified for your Aquadyne filter.

• AD1000 / Model .30B --- Requires  11  lbs. 
• AD2000 / Model .60B ---  Requires  20  lbs.
• AD4000 / Model 1.1B --- Requires  40  lbs.
• AD8000 / Model 2.2B --- Requires  80  lbs.
• AD8000HE / Model 2.2Bhe --- Requires  80  lbs.
• AD16000 / Model 4.4C -   Requires  160  lbs.
• AD30000 / Model 8.8C -- Requires  320  lbs.
• Ecosphere 10/20   --- Requires  10  lbs.
• Ecosphere 40/80   --- Requires  40  lbs.