Keep Your UV Bulb Shining Bright

A UV unit is a great addition to your pond filtration system. It removes green algae from your pond by passing the water over an ultraviolet light. UV units are particularly useful for pond keepers who want a great view of their Koi stock.


However, UV bulbs do not last forever and can expire, just like a conventional light bulb. The bulb is the most vital component of your UV system and without a working light-source, your unit will not be able to perform its function.

 A UV lamp does not just need a working bulb. It relies on having a very bright light in order to clear pond water effectively. Over time, you may notice green algae becoming more visible in your pond. This is because UV bulbs can lose their potency with use.

For this reason, it is important to check your bulbs regularly. PLL and PLS bulbs should be replaced every 12 months. For linear tubes, replacement should take place every 6 months.

Green algae is most likely to appear during spring, so changing your UV bulb in March or April will ensure that your light is at its strongest when you need it most.


Changing your UV bulb

(This is just a guide. Please follow the instructions for your unit carefully)

  •  Unplug your unit and detach the water supply
  • Unscrew any side panels and slide out the old bulb.
  • Next, carefully insert the new bulb into the socket, before closing the unit.  Make sure all parts are screwed together tightly.
  • Reconnect the water-source before switching on your UV unit.


UV bulbs can also short because of water damage. As we know, electricity and water do not mix and UV units come with specialist components to ensure that they are protected.


Quartz is water-resistant but it can crack. If water enters the UV unit it will cause a short circuit and your UV bulb will be rendered useless.  In this instance, it is imperative to replace the quartz sleeve as well as the bulb.


Changing your Quartz sleeve

 (This is just a guide. Please follow the instructions for your unit carefully)

  • Repeat the process for removing the bulb, above.
  • Always handle quartz with gloves, as it marks very easily.
  • Once the chamber is open remove the O-rings and slide out the quartz. At this point water may leak from your UV unit, so be prepared.
  • Insert the new quartz sleeve, before replacing the O-rings.
  • Next insert your new bulb and close the unit tightly


As incidents can occur when it comes to UV filtration systems, it is a good idea to keep a stock of pond spares in your garden shed.

You can buy spare UV bulbs and Quartz Sleeves from Aquatix-2u

For a wide range of pond spare parts, including O-rings, screws and other small parts visit our pond spares page.