Merc Vapor Pros
1. Higher amount of uvb
2. Able to be effective at greater distances especially with spots
3. Can last longer (if it doesnt fail) cause with higher uvb from the start the decay at end of bulb life is a higher uvb amount. (uvb bulbs put out less uvb because the uvb rays change the structure of the glass in the bulb causing less uvb to be able to come through)
4. Can rehabilitate MBD more effectively
5. A good option if your setup prevents you from getting a 5.0 Zoomed 12 inches or closer to the basking animal.
Merc Vapor Cons
1. Notorious for failing early (not going on anymore) especially if moved or jostled. average life is 3 - 6 months in which case it needs to be sent back and most if not all manufacturers will credit with a prorrated amount. A big hassle contantly mailing back bulbs. However I have found that the externally ballasted ones hardly ever fail. They are the only ones I would ever use. I have 60 watt External ballasted ones from active uvheat or from westron (which is who active gets them from).
2. Very small area of uvb. Since purchasing a uvb meter I have been suprised at the fact that the animal has to sit right smack in the middle of the beam even with floods. the sweetspot sometimes being only as large as a silver dollar. also the distance on various bulbs will be critical as there is an optimum distance in addition to farther away, moving closer to the bulb will actually give LESS uvb. There is an optimum distance depending on the distace each bulb will focus the beam to. the Zoomed 5.0s although weaker uvb casts it out over a much larger area there is no sweet spot. simply put the closer to the bulb the more uvb. Also the ends of the ZM bulb has less uvb than the middle.
3. I dont like the color of the light its not a nice white light like the 5500K zoo meds
4. Dont look directly at the bulb while being close to it. also keep it shielded from people. If this is followed i believe they are safe
5. not to be used for small enclosures.
Conclusion
For my 2 large desert vivarium setups I use both types (5.0 and 60w Ext. Ballasted Merc vapor) I have the MV lights only go on for an hour 2 times a day while the zoomeds are on the whole time the heat is on. This will prolong the life of the MV bulbs. Also the ballast on flour. fixtures you use for the zoomeds varies. I have found quick or rapidstart ballasts put out twice as much uvb numbers with the same bulb.
not sure if this fact is consisent with all RS or QS ballasts. The more expensive fixtures are probably generally better to buy .
also I believe from reading test reports of people with uvb meters that the the zoomed 5.0 or iguana light is the best of the Flourescents for having higher amounts of uvb.
I hope this post has been......gag, wretch......enlightening
John Styner
