Hi,
If your UV has been running for three years it is not effective any more.
The fact that the light still glows is not a factor. They lose their
effectiveness gradually as time passes losing, IIRC, about 60% in the first
9 months. The good news is that your water is clear. I would not replace the
bulb at this time. IMHO UV clarifiers are usually not required.
To reply personally remember no "NEWS" is good.

"Oxymel of Squill" wrote in message
news:GkF0c.1436$vY.486@newsfe1-win...
Anyone kno anything about uv lamps in filters.
snip