See this is the problem... By telling people that they can wait a year or over a year to replace your putting their cham at risk.
OK, first, please don't put words in my mouth. I did not tell
anyone, "that they can wait a year or over a year to replace". I said that Reptisun T5 bulbs should last 12 months according to everything credible that I can find, including their warranty,
and I provided citations to back up what I found.
We give these basic guidelines because 1 out of every 10 are going to get a solarmeter 6.5. So that leaves the other 9 that will not.
Then why hasn't it occurred to anyone to tell people to
get a Solarmeter—that it's an essential piece of equipment for keeping a healthy
chameleon diurnal reptile? We tell them to get an enclosure of a certain size, what supplements, what tests, what veterinarians, what plants and that they should be live instead of plastic, what feeders to get, what thermometers & hygrometers, how often to mist, and... what lighting to provide—everything essential to good husbandry
except the one piece of equipment that will ensure not risking their chameleon's getting MBD. Why not a UVB meter?
Why is it OK to do this on the cheap‽ People are spending hundreds of dollars on enclosures, and hundreds of dollars on lighting (over time, at least) but not the extra to know if the UVB is working properly? IMO, that makes no sense.
What if someone gets a defective bulb? I got one, and if I hadn't had the meter, I wouldn't have known, I would've been out the money, and my pet would have been at risk.
By telling them not to replace at 6-9 months you now risk their cham. These bulbs are not equal to one another. Even an arcadia bulb will start to put out less UVB the longer it is used. So we stick to the rule of thumb because being responsible for a chams death is not something we want to take on.
I'M not risking
anyone's cham. The only place I'll go out on a limb to say is,
if someone can't afford everything necessary to provide proper husbandry for a chameleon, then perhaps they should think about getting a less expensive to care for pet. (OMG!—He
said it!

) I have too many veterinarians in my social network not to have heard too many horror stories about people who shouldn't keep animals because they either can't—or more likely
won't—spend what's necessary to properly care for them.
Yes, all UVB bulbs lose efficacy in time—that's not the issue.
I think your rule of thumb is based on outdated—or mis—information.
Why aren't people
screaming about this "blatant misrepresentation" on the part of Reptisun?
Please—show me some credible citation, study, etc. that says Reptisun's T5's don't last 12 months. I'd be happy to recant, retract, eat my words, whatever... But I can't find any such evidence, and so far, no-one else has produced any. Anecdotal evidence, while not worthless, has some problems. How do we know the bulb wasn't defective? How do we know it wasn't old, returned by someone else after some use and resold, or damaged in some way?
I'm not angry, but I'm a little frustrated that meanings are being assigned to me that I haven't said or expressed.