Size Your Replacement Bulb
Step 1: Identify your bulb's base to verify that it matches the picture.
Step 2: Locate your bulbs wattage.
Step 3: Measure your bulb end to end (including pins) to confirm which replacement bulb is correct for you.
The 2G11 Base 18 Watt UV Bulb is used as a replacement for the following: TetraPond® GreenFree® UV Clarifier