[Steve Nguyen]

technically, the dealer/manuf. recommends to replace the bulb on yearly basis if you want optimal performance. haven't replace my yet after two years and it's still working fine so far.

in your case, have you clean the sleeve jacket? ( think that's what it's called) this should be done on yearly basis as well. I would say it should be cleaning every six months if the UV light is positioned on before the pre-filter or in first stage of filter or settling tank. if you put the UV light just before the water return to the pond, there will be less build up since the water already pass thru the filter media. remembers that algae won't be killed unless it exposes to UV lights. if there's a build up, not much UV light will expose. be careful when clean the sleeve jacket. it's very fragile.

Steve

Quote: Originally Posted by Dale Torok Russell Peters made a very good point about turning bulbs on and off shortening the life of the bulb. It happened to me. Three years ago I installed two UV filters on my pond. I ran them 24/7 for two seasons except for turning them off during the winter months. The water stayed clear. Last spring (start of the 3rd season for the bulbs), I started getting a tinge of green that continued to worsen. Then the water REALLY turned green. I bought new bulbs. The water cleared in about 10 days. When I remarked to a friend that the bulbs were so darn expensive, he said, "Why don't you put them on a timer? 12 hours on during daylight and off 12 hours every night. That way the bulbs ought to last four years instead of only two." It made sense to me, so that's what I did. Last year the UV bulbs were on 12 off 12 for the full season. The water stayed crystal clear. This spring, a few weeks after I turned the UV filters back on, the water started the green tinge thing and began to get worse. I could see where it was going, so the bulbs were replaced. I only got one season out of this set of bulbs. Apparently, turning bulbs off and on every day puts much more wear and tear on them than simply leaving them on all the time. Dale