Pond essentials
What a UV clarifier does
A UV clarifier can help control suspended green-water algae. It does not remove the need to test water.
Match the specification
Use the correct flow range, lamp type and pond/fish rating. Water travelling too quickly through a unit may not receive the intended exposure. Fit it in the manufacturer’s recommended position.
Keep it working
Replace lamps and clean quartz sleeves according to the unit’s instructions. A lamp appearing to glow does not prove useful UV output remains. Isolate electrics before servicing and never look directly at an operating UV source.
Know its limits
A clear-looking pond may still have ammonia, nitrite or insufficient oxygen. A clarifier does not substitute for mechanical cleaning or a mature biological filter, and it is not a treatment for every fish illness.
If water stays green
Check the actual flow and lamp age first. Also review sunlight, feeding, stocking and maintenance. Avoid adding multiple treatments while troubleshooting the same problem.
Keep the unit details
Record the UV model, lamp part number, lamp-change date and cleaning date. A photograph of the data label is more useful when finding a replacement than the pond volume alone.
Sources & further reading
Original WakeyKoi wording, informed by the references below. Linked clinical resources explain the evidence and their scope; they have not reviewed or endorsed this website.
Related guides
Educational guidance cannot diagnose an individual fish. Breathing distress, severe injury or unexplained losses need prompt professional assessment.