Generally you should rebuild your pond aerator compressor unit every 3-5 years under normal conditions.  Air filters should be changed or cleaned once or twice a year. 

Pond Aeration Rebuild Kits & Filters

SRC Stratus Compressor Rebuild Kits Fits Gast
SRC Stratus Compressor Rebuild Kits Fits Gast
$65.59
Stratus SRC series "Gen 2" rocking piston compressors are specifically designed for the demanding job of 24 hour...
Air Filter for Rocking Piston Compressors
Air Filter for Rocking Piston Compressors
$43.09
Air Filter for Rocking Piston Compressors Gast Replacement Element Only - GAFE Replacement filter element for GAF and GAF2 filters...
Replacement Air Filter Element for DC22
Replacement Air Filter Element for DC22
$19.69
Gast Replacement Air Filter Element for DC22 compressor
Rotary Vane Compressor Parts
Rotary Vane Compressor Parts
$4.59
Rotary Vane Compressor Parts - Gast Rotary Vane Repair Kits Rotary vane compressors each have four self-wearing carbon vanes,...
Gast Blower Filter 1/8 HP to 5 HP
Gast Blower Filter 1/8 HP to 5 HP
$21.29
Gast Blower Filter 1/8 HP to 5 HP Use these high volume air filters as replacements on Gast...
Check Valve For Rotary Vane Compressor
Check Valve For Rotary Vane Compressor
$29.99
Check Valve For Rotary Vane Compressor The RVC/ RVC2 assembly is designed to go on the inlet of the...
1/8 and 1/20 HP Gast Compressor Repair Kit
1/8 and 1/20 HP Gast Compressor Repair Kit
$83.39
1/8 and 1/20 HP Gast Compressor Repair Kit - DC12RK, RK22 If your air compressor runs but does not...
1/4 HP Gast Rocking Piston Compressor
1/4 HP Gast Rocking Piston Compressor
$544.99
1/4 HP Gast Rocking Piston Compressor - Stratus SRC Series Gen2 Rocking Piston Compressor - SRC25 - FREE SHIPPING...
1/4 HP Gast Rotary Vane Compressor
1/4 HP Gast Rotary Vane Compressor
$749.99
1/4 HP Gast Rotary Vane Compressor - RV33 Stratus Long lasting, continuous duty compressors offer less depth capabilities...
Vane Repair Kits - RV33, RV75, RV100 Gast Compressors
Vane Repair Kits - RV33, RV75, RV100 Gast Compressors
$109.89
Gast Rotary Vane Compressos are long lasting and continuous duty compressors that hve less depth capabilities than the rocking...
SRC Stratus Compressor Rebuild Kits Fits Gast
SRC Stratus Compressor Rebuild Kits Fits Gast
$74.29
Air Filter for Rocking Piston Compressors
Air Filter for Rocking Piston Compressors
$43.09
Replacement Air Filter Element for DC22
Replacement Air Filter Element for DC22
$19.69
Rotary Vane Compressor Parts
Rotary Vane Compressor Parts
$120.29
Gast Blower Filter 1/8 HP to 5 HP
Gast Blower Filter 1/8 HP to 5 HP
$51.19
Check Valve For Rotary Vane Compressor
Check Valve For Rotary Vane Compressor
$32.59
1/8 and 1/20 HP Gast Compressor Repair Kit
1/8 and 1/20 HP Gast Compressor Repair Kit
$84.39
1/4 HP Gast Rocking Piston Compressor
1/4 HP Gast Rocking Piston Compressor
$544.99
1/4 HP Gast Rotary Vane Compressor
1/4 HP Gast Rotary Vane Compressor
$749.99
Vane Repair Kits - RV33, RV75, RV100 Gast Compressors
Vane Repair Kits - RV33, RV75, RV100 Gast Compressors
$109.89