Ultraviolet light

[BlueMars]

I heard that using ultraviolet light in the water-pump line of a pond kills the green water algae. I was wondering if theres an inexpensive method of creating ultraviolet light? I've seen these kits selling for $200 and up. Unfortunately, it's a small pond and I dont have this kind of money to spend on it. Does anyone know any inexpensive projects/methods to create this UV light?

Thanks in advance,

[blackeagle]

Every fluorescent light produces UV light but normally the tube is coloured with a fluorescent colour to transform UV light in visible light
then you can buy a UV tube (it doesn't cost too much) and give it the current to work by a starter and a "reactor"
my english is not very good then my explanation may be not easy to understand...

[loalight]

Well, you could buy an old transilluminator off of ebay, like this one: http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

These tubes produce hard UV, which does a far more effective job of killing beasties (and blinding you!) than the 'black light blue' fluorescent tubes.

You'd also want to make sure the tubing through which you are piping the water is UV-resistant- otherwise, after a few weeks of use, the UV will just eat many plastic/rubber tubes away..

good luck!

[Zelandeth]

Fluorescent and germicidal tubes are electrically and physically compatable. So simple solution would be to find yourself a fluorescent fixture, and a germicidal tube of the same type (same number as the fluorescent one, but with a G prefix rather than an F prefix).

It's worth noting however that you'd have to have the water open to the light, unless you're using a bit of quartz piping past it or something, as glass and most plastics absorb the shortwave UV which is actually doing the work.

Also, safety is a major concern here. Aside from the obvious horrible combination of high voltage electricity and water, the shortwave UV these lamps output is VERY, VERY harmful to living organisms - you included.

Good descriptions of this sort of thing can be found here:

Don Klipstein's Light Site

Don's page on UV lamps, Germicidal section.

Hope that helps.

[BB]

Here is one manufacturer of UV light assemblies for fish ponds:

Aqua Ultraviolet

My father-in-law has two 40 watt units in series for a 2,000 gallon Koi pond. The bulbs died and before we noticed and ordered replacements, the pond bloomed green with algae. After about 1 week with new tubes, the pond was back to normal.

The tubes last about 1 year (turning on and of often will dramatically shorten their lives).

The assemblies are pretty simple, but there is a lot of design work to make sure that they last and don't electrocute anyone.

-Bill