I have an enclosure that uses two uvb tubes at 24" in length. Recently purchase two but have a question as to determine when these tubes loss their ability to properly supply uvb. I have used my local pet store in the past to determine the "life-left" in older uvb tubes, however a recent incident at this particular store has left doubt in my mind that these tests are actually legitimate, meaning more like a sales tactic to purchase replacements, while in their store. So how can I really tell the value of these bulbs as they age? BTW...Repti-Sun 10.0 24". Thanks for any advice offered.
The only true way (that i know of) is buying a solarmeter which tells you exactly when to replace it by testing how much uvb exposure your beardie is getting inside the tank. However they cost around 200-300 and more.
Generally you want to replace bulbs every 6 months, some can go longer while others stop earlier. My juvenile beardie actually refused her food, became in active and everything once the 6 month mark hit for hers (reptisun t5 HO 10.0 46" tube light) so i had to switch some bulbs around and right after i switched it with a 1 month bulb she perked up within a few hours.
So...what I've read an understand from a lot of posts on this site, uvb light sources usually fade from proficient life after 6-7 months...is this a fairly accurate statement? Seems like that's a quick life. Is there another alternative that would give me more like a year of life service? Reach from dragon back to surface of light source is 9". A screw-in halogen/uvb would put heat source too close to Rocky. Presently, for heat, I use par-20's(2) 8" apart which are sandwiched between the two 24" fluorescent repti-sun 10.0s
Yes a Solarmeter is the best way to check output from a light. I use a Solarmeter 6.5 to check mine. It measures UVIndex. The general (conservative, for good reason) estimates are that a T8 tube will need replacement every 6 months or so. A T5 tube will need replacement every 12 months or so. Sometimes they last much longer but not always. Sometimes they degrade more quickly. That's why it's important to use a reputable company with good quality control such as ZooMed ReptiSun or Arcadia - less likely to have underachieving bulbs. My Arcadia T5 has been producing excellent UVB for 3 years now but that may not be the case every time. Best to check with a Solarmeter.