You can make your own uv, but it needs the bulb inclosed in a pipe type
structure with the water flowing past the bulb. The uv has a fairly poor
penetration through the water, particularly if it is cloudy or green water,
so to get the uv to do anything, it should probably be no more than 2 inches
from the farthest water you are trying to treat. UV is very dangerous. It
will burn the retina of your eyes fairly quickly, and over longer exposures
cause skin cancer, so the UV needs to placed in a light box or other
enclosure to prevent skin or eye exposure. From the catalogs, the cost of
the ballast, bulb and quartz tube adds up to more than the cost of a
complete unit. I would buy, either from ebay, an online store or a local
dealer, based on price. Recopgnize that the bulb needs to be replaced after
about 12 months of operation, so a source for the bulbs needs to be
considered in the price.
"Webfoot" wrote in message
...
I am using a laundry sink for my upflow filter. Why cant I just hang
a UV light over it and save $200?

Russell Mack