Check the listing for details. 11 Watt PLS UVC Germicidal Replacement Bulb Lamp for Pond Filter. Condition: New. Listed at 17.95 USD. 11 Watt PLS UVC Replacement Bulb This 11 Watt PLS UV-C Germicidal Replacement plug in Lamp has a miniature bi-pin base and emits germicidal UV light...Greenwater or single cell algae problems in Water Garden Ponds can be eradicated using a UV light clarifier. UV-C light germicidal Ultraviolet lamp or Ultraviolet UV Germicidal Bulbs help control the growth of algae. The increased water clarity improves fish viewing and it also improves the health of the fish. • PLS Type H Glass • G23 Base (13 Watts is GX23 Base) • 11W - 9.2" (234mm) •Quartz Glass Construction • Use in Pond Filters, Water Purifiers, Etc. •For Best Results Change Every 6 Months or 8000 hours We Sell Many UV Bulbs Online, Check out our eBay Store!!! Terms and Conditions. We use all approved forms for accepting payments. Sales Tax will be added to all shipments based on regulations. We always try to combine purchases, please contact us directly for a personal service. You will be notified on the day that your goods have been dispatched via e-mail with tracking which is used on all purchases. Please note that if there are any problems, contact us first via e-mail giving full details of any problem along with your user ID. We use USPS and UPS as our chosen carriers shipments to Hawaii, Alaska & Puerto Rico may incur surcharges, contact will be made to advise before shipment at which point the order can be canceled if desired. Orders placed on Saturday/Sunday & Public Holidays will be processed next working day. We pride ourselves on excellent feedback, if any part of the buying experience is not to your satisfaction, please contact us to rectify before leaving feedback. By committing to buy you are agreeing to the Terms & Conditions stated above.