I get that we should change our bulbs once a year but, I have a Pentair 40w (and 25w on a different tank) that I serviced yesterday. It’s been running 24/7 with a 10 minute break at midnight, why, not sure, one of life’s many mysteries. When I inspected the bulb, the ends have slight dark spotting, I just changed a bulb in the other unit that had been running for a year, and the bulbs looked similar, this 40w was purchased brand new, so I know it’s history, unlike the 25w. However, when I took the the sleeve out I was shocked at how much calcification after 3-4 months was on the sleeve. I think the UV may have been nearly useless with this level of calcification. For those that service, is this normal?
