UVB tubes emitting different colours?

[RGX]

Hi, bit of a weird one this.

I have a large enclosure for my beardie with two long UVB tubes running inside the viv, one on either side of the longest part of the enclosure. I recently replaced the UVB tube above the basking spot as it was over 6 months, planning to replace the other soon after. Today, the UVB on the nearest side (not above the basking spot) blew, so I replaced it with an old one I had lying around as a temporary measure untill I can buy a new bulb.

They are both Exo Terra reptile UVB 150s, 30 watts each, 36" long. One is brand new, one has had 6 months of usage on it. The new bulb is producing a white, almost warm light. However, the old bulb is producing a much bluer, colder type of light. Shouldnt this be the other way around? I've done the paper test and the old bulb seems to make the paper turn slightly more purple. Doesn't this mean the old bulb is producing more UVB light than the new one? I will get a new bulb for the non-basking side regardless to replace the old one but I'm slightly worried that the "new" bulb I've put above the basking spot is not putting out the level of UVB it should and therefore is bad for my dragon.

Essentially, my question is this: What colour should the bulbs be emitting when they are in the best condition, white to yellow or white to blue? Is my new bulb doing what it should? And if so, is the old bulb (which is emitting a much bluer light on the far (non-basking) side of the tank) going to cause any issues for my dragon in the meantime while I get a replacement?

Thanks for any help provided.

 

[KarrieRee]

TBH I would get rid of the Exo Terra and replace w/ a Reptsiun 10.0 T 5 bulb -- they are the best on the market along w/ the Arcadia 12% bulb at this time -- they need to be changed out in approx a year I change mine out a month prior to

 

[RGX]

TBH I would get rid of the Exo Terra and replace w/ a Reptsiun 10.0 T 5 bulb -- they are the best on the market along w/ the Arcadia 12% bulb at this time -- they need to be changed out in approx a year I change mine out a month prior to

Appreciated, and shall do next time, although seeing as I have a brand new £30 bulb in my tank id like to know if it was working properly or not before buying a new one, even if its not the best model.

 

[KarrieRee]

Not sure you can PM Cooper dragon----- find his name on the board click on it his profile will come up left side find pm

 

[Claudiusx]

Hi there,

Even if the bulb was hardly used, the elements in them can start to break down over time, that might explain the difference in color.

Unfortunately, there is no way to tell if it's producing proper UV based of the color it emits, or a paper test. The only way to test would be with a solar meter which I assume you don't have otherwise you wouldn't need to ask about it :mrgreen: Expensive machines, but can come in handy!

How big is your enclosure? Are the tubes running side to side like this _ _ or are they like this =? (pardon my example drawings lol).

Ultimately, you won't be able to get a definitive answer from us on the forum because there is no way to test your bulb without actually testing it. So either your bulb is doing nothing worthwhile, or it is. If you want to be safe and you think your tank needs the two bulbs, it'd be best to replace it unfortunately.

-Brandon