Algae Control - No More Green Water

What is the difference between a UV clarifier and a UV steriliser?

UV clarifiers are used to kill algae along with some disease organisms. The water flows through UV-clarifiers faster than UV sterilisers.

UV sterilisers kill 99% of floating algae as well as other living organisms. Using a UV steriliser does not harm the beneficial bacteria that grow in filters or on the pond walls etc. They only kill the living organisms that are in the pond water that is passed through the steriliser.

For koi keeping it is best to opt for a steriliser because they not only kill the algae making the water crystal clear, but as the term 'steriliser' infers, they also sterilise the water itself, thus helping to kill the harmful bacteria that lives in water. The UV sterilisers will also kill some foms of water born pathogens.

How does a UV filter clear green water?

Single celled green algae, (Chloella Vulgaris) require light and nutrients to thrive. Under normal circumstances this is a sign that your pond is generally heathy, and it even makes a great food source for farm animals, but unfortunately it doesn't do much for your overall enjoyment of viewing koi.

The small algae cells can pass through all conventional filters, so physically filtering them out of the water in their normal form is next to impossible. However, passing the cells through a UV disrupts theit internal structure, if not actually killing them, at which point they clump together or 'flocculate' . These clumps can then be trapped and broken down by the filtration system.

When to use a UV?

Most koi keepers will keep their UV unit on all year round, especially if using a steriliser to keep the water in tip top condition. However, for small garden ponds you may find that only in the spring, with the combination of longer days and an upsurge is fish activity, is the UV necessary. If you do run your UV all year round, it must be protected from frost in a well ventilated housing. Remember it is important to replace your UV lamps annually for peak performance.

How much UV do you need for a pond?

Purely for green water eradication, 8 - 10 watts per 1000 gallons is a good starting point. But some pond keepers will maintain that, for reduction in bacterial levels, this can be increased to 30 watts per 1000 gallons. Other factors to consider are of course flow rates, stocking levels and the direct sunlight that the pond is exposed to: ponds in shade require less UV power.

Should you have any questions regarding UV or UV sterilisers than please don't hesitate to contact us , we'll be only too happy to help.