Charles Austen UVC Series
Charles Austen UVC Pond Clarifiers
Seven inline models from UVC5 to UVC36 for green-water control in garden ponds
The Charles Austen UVC range provides a sensible staircase from small ponds to systems needing up to the published 5,600 l/h maximum flow. The family runs from UVC5 through UVC7, UVC9, UVC11, UVC18 and UVC24 to UVC36.
One detail is worth spelling out: the model number and total electrical consumption are not always identical. For example, UVC11 is listed at 12 W consumption, UVC9 at 10 W and UVC5 at 7.5 W. Use the exact product table rather than guessing from the name.
These are clarifiers for water pumped through an inline chamber. They help the filter remove suspended green algae; they do not replace mechanical and biological filtration.
Charles Austen UVC Model Comparison
| Model | Published maximum flow | Rated consumption |
|---|---|---|
| UVC5 | 1,100 l/h | 7.5 W |
| UVC7 | 1,500 l/h | 8.5 W |
| UVC9 | 2,000 l/h | 10 W |
| UVC11 | 2,700 l/h | 12 W |
| UVC18 | 2,800 l/h | 18 W |
| UVC24 | 3,700 l/h | 24 W |
| UVC36 | 5,600 l/h | 36 W |
Published maximum flow is a ceiling, not automatically the preferred flow for every pond or treatment target. Use the current manufacturer sizing guidance.
Do Not Overspeed the UV
For green-water control, water needs sufficient exposure inside the chamber. A very large pump forced through a small UVC can reduce the effective dose. If the filter needs more total turnover, a bypass can be used only where correctly designed and permitted.
Measure or estimate the real branch flow after pipe losses, not the pump’s dry headline figure.
Keep the Unit Working Properly
Clean the quartz sleeve, inspect O-rings and replace the correct lamp on schedule. A visibly glowing lamp may have too little useful UV-C output left to control algae.
Our advice: when replacing an old unit, send us its model and your actual pump flow. We can check both hydraulic and lamp sizing.
Related Categories and Spares
All pond UV clarifiers · Replacement UV bulbs · Charles Austen pond pumps · Pond filters · Pond pipework
Frequently Asked Questions
What is the smallest Charles Austen UVC?
UVC5, with a published maximum flow of 1,100 l/h.
What is the largest model?
UVC36, with a published maximum flow of 5,600 l/h.
Does UVC11 consume exactly 11 watts?
The current listing states 12 W total consumption.
Why are UVC11 and UVC18 flow figures close?
They are different lamp and chamber duties; use the current manufacturer sizing rather than assuming a linear model sequence.
Can I run 5,600 l/h through UVC36 on every pond?
That is a published maximum. The preferred flow may be lower for the required UV dose.
Can I mount the unit in any direction?
Use only the orientations allowed in the installation instructions, keeping the chamber full and serviceable.
What should I send for a replacement check?
Pond volume, pump model, hose bore, filter layout and the old UV model.
Will a UV clarifier remove blanket weed?
No. UV-C can help with single-celled algae carried through the unit, which is what causes green water. Attached algae and blanket weed need a different approach.
Does clearer water mean the pond filter is no longer needed?
No. UV treatment clumps suspended algae, but the mechanical filter still has to collect it and the biological filter still processes fish waste.
Can I choose a UV only by wattage?
Not reliably. Pond volume, flow rate, fish load, sunlight, chamber design and the manufacturer’s recommended dose all matter.
Why does the quartz sleeve need cleaning?
Limescale and biofilm reduce the UV reaching the water even when the lamp is working. A clean sleeve is essential to useful output.
Can I look at a lit UV-C lamp?
No. UV-C can injure eyes and skin. Isolate the electrical supply before opening the unit and follow the manufacturer’s safety instructions.
Should the UV run before or after the biological filter?
Follow the system and manufacturer layout. The important points are the permitted flow, correct orientation, full water coverage and safe access for servicing.
Can you check which model suits my pond?
Yes. Tell us the pond volume, fish stock, pump flow, pipe size, filter model and whether the pond is in full sun.
When should I replace the lamp?
Use the interval stated for the exact lamp and unit. UV-C output falls with age even when the lamp still produces visible light.
