Too much UVB?

[Hannah04]

I have read many threads on here in regards to lighting. I have also asked many questions. And have taken a lot of advice for changing things. I went out and bought an exo terra reptiglo 5.0 tube light. I already have an exo terra 5.0 compact. Here are some questions I need help with!

Is running both of the bulbs going to be two much along with the basking light?

I have read that screens block out 50% of UVB? So would that make my 5.0 UVB (5% UVB) actually only 2.5%? Is it going to be better to run both for ore coverage? Since right now there is only uvb coverage in one corner?

Thanks
Hannah

 

[bradley]

The only of getting more uv in the cage is by using a stover bulb such as a 10,0. Using two 5.0 bulbs will just provide 5.0 over a larger area not double the strength.

 

[Hannah04]

The only of getting more uv in the cage is by using a stover bulb such as a 10,0. Using two 5.0 bulbs will just provide 5.0 over a larger area not double the strength.

Perfect! Thanks so much!

I don't need more i don't think, just more coverage for him!

 

[nightanole]

reptiglo makes a 5.0? I thought they only sold 6 and 12.

Anyway my vote is 1 tube with a reflector. That will put about 2/3 more uv into the cage vs getting absorbed into the white part of the hood. I wouldnt replace the cfl 5.0 after its 6 months are up. just throw it away and use only the tube.

In the long run you can look into the new 5.0/6% T5 HO bulbs from zoomed and arcadia. They only need to be replaced yearly and make the cage alot brighter.

 

[Venutus1]

The only of getting more uv in the cage is by using a stover bulb such as a 10,0. Using two 5.0 bulbs will just provide 5.0 over a larger area not double the strength.

Sorry, but I must point out for safety sake:

This IS FALSE.



UV light behaves as regular light does.

Twice as much = twice as bright.

True, the UV may be spread out a bit more ...

but it will be STRONGER... no doubt about it because the UV is also twice a "bright" ...

Because twice as much light is being emitted with 2 bulbs over a given area.

Just 'cause our eyes we cant see it, doesn't mean its not there.

MORE REASON TO NOT FOOL AROUND AND GET A SOLARMETER.

There are way too many "myths" about UV like this floating around out there.
I have run across this particular one allot lately.

Cheers!
Todd

 

[Hannah04]

Todd, what would you recommend doing?

 

[Venutus1]

I have read many threads on here in regards to lighting. I have also asked many questions. And have taken a lot of advice for changing things. I went out and bought an exo terra reptiglo 5.0 tube light. I already have an exo terra 5.0 compact. Here are some questions I need help with!

Is running both of the bulbs going to be two much along with the basking light?

I have read that screens block out 50% of UVB? So would that make my 5.0 UVB (5% UVB) actually only 2.5%? Is it going to be better to run both for ore coverage? Since right now there is only uvb coverage in one corner?

Thanks
Hannah

Hi Hannah,

Screen does block some UV, but usually it is no more than say 20 - 25%.

I think what you are saying is that you have a Repti Glo CFL 5.0 and a linear tube. Used in conjunction.

Exo Terra Repti Glo's are...umm... well.... not that strong. To put it politically correct.
They are Chinese made and the ones I have personally tested seem to have all low UV out-put.

So...
I doubt you are going to over UV your animal, but I can not say for sure.
Can you please post a pic of the enclosure / set up?


The only way to tell for sure is with a Solarmeter.


And as far as the 5.0 meaning...
What they are saying /claiming is that 5% of the overall output of the light energy put out by that bulb is in the UVB range.

But that ultimately can have little bearing on what is REALLY reaching the animals!

Cheers!
Thanks
Todd

 

[Venutus1]

Some Single and Double Bulb UV Readings

Going back to the whole

"if you use two 5% bulbs you sill get 5% UV thing"

that has so many confused.

PLEASE!
Don't feel bad if you are one of the confused... I get e-mails on it every day.

and YES!
By adding one, two, three ... five, how ever many UV 5% bulbs...
You are still getting light that is (in theory) made up of "5%" UVB Light Energy.

But you are getting more of it by adding bulbs--
so not only is the visible light stronger (brighter/more intense)...
BUT THE UV IS TOO.

So stronger is giving you higher UV readings.

I have these pics of some Arcadia ho t5's in both 6% and 12%.

They are in the double bulb fixtures.

Please note how you can CONTROL UV by adjusting ratio of UV Bulbs with regular 6.5k daylight bulbs. That is what makes double bulb and quad bulb fixtures so cool! And you get ooodles of light for plants.
Just provide ample shade too, like the animals would get in Nature.

ALWAYS LOOK TO NATURE TO SHOW US THE WAY.

Disclaimers:
There are many factors that influence strength of UV.
Here are just some:

1.
Age of bulbs.
All UV bulbs loose UV out-put over time, some cheaper brands MUCH faster than others.
(but I don't sell those kinds that loose it fast. )

2.
The Reflector set-up.

3.
Number of bulbs side by side in fixtures (a bulb beside another creates a non reflective surface that can actually cut down on UV a bit.)

4.
Screening
Screening will cut down UV light AS MUCH AS IT CUTS DOWN VISIBLE LIGHT.
Thus:
If the screening is reducing / blocking the visible light by... say... 15%,
it will also be reducing UV light by approx. 15% too.
UV Light behaves as visible light does through screening.(but not glass... see below.)

5.
Glass
Normal Glass filters out 98%- 100% of all UVB.
Special quartz glass allows (some or most) UVB to pass un-filtered.

Plexi glass also filters UV -
But Solacryl like they use on Tanning beds does not filter out (much) UVB.


About these pictures and readings below.....

I did them quick with minimal fussing about, so there may be a slight variances.

These are brand new bulbs in the pictures.
So they are at the most potent.
And the distance is at approx. 10".

And because they are in a double bulb fixture, the non reflective surface of the "neighboring" bulb reduces what is getting reflected.
The single bulb readings would be a bit higher if the bulbs were alone in a single bulb future with a perfect parabolic reflector.
I hope that made sense.?

Anyway, please see how doubling the UV producing bulbs virtually DOUBLES the UV.
And...
See how much UV is given by ONE 12% in relation to using TWO 6% bulbs.

Thank you and Cheers!
Todd

please click on thumbnails to enlarge. thanks.

 

[lilacdragon]

Important info on multiple UV lamps

Todd is absolutely right.
Light and UV is additive. Think of stage lighting - two spotlights aimed at the same spot will double the illumination on the person on stage.

This is a wonderful effect for large enclosures. But be VERY careful, if you have multiple high-output lamps in a big enclosure, and your chameleon can climb right up under the set-up, because of the way light and UV decrease with distance.
If you are getting perfect UV readings at 12" away.... then any closer than 12", the readings will be too high! A really powerful multi-tube T5 unit, for example, can create sunlight-strength UVB 3feet below it, but of course any closer than 3ft will be too strong for the chameleon.
It's a wonderful thing but like all powerful energy sources (heat, electricity, magnetism) needs handling with respect.

By the way....some mesh fly-screens (eg. ExoTerra wire mesh, Reptarium mesh etc) can block a lot more light and UVB than others. I've tested many types and typically they block about 30 - 35%, but very dense ones can block 50%. The only one I've tested that only blocks about 15% is quarter-inch twillweld, which is extremely wide wire mesh, the sort you buy in DIY stores for making chicken pens etc. I use it a lot when making my reptile vivaria but it's no good for preventing insect escapes LOL!

Best wishes,

Frances Baines

 

[Route Flux]

Sorry, but I must point out for safety sake:

This IS FALSE.



UV light behaves as regular light does.

Twice as much = twice as bright.

True, the UV may be spread out a bit more ...

but it will be STRONGER... no doubt about it because the UV is also twice a "bright" ...

Because twice as much light is being emitted with 2 bulbs over a given area.

Just 'cause our eyes we cant see it, doesn't mean its not there.

MORE REASON TO NOT FOOL AROUND AND GET A SOLARMETER.

There are way too many "myths" about UV like this floating around out there.
I have run across this particular one allot lately.

Cheers!
Todd

I think this thread is a bit misleading...
The photoelectric effect tells us that no matter the intensity of the light (no matter the brightness or amount of light) the kinetic energy does not change.

This means that as long as the frequency is the same, you are just doing more of the same thing.

If the frequency is increased above a certain threshold than changes occur.
As far as light goes you should be able to put as many bulbs as you want with the same physical effect.

You just cover more area with it. If you shine more spotlights on yourself sure you increase the area the light covers but physically it is harmless, except maybe to your eyes.

All that being said I don't think anyone intends to surround an enclosure with lights and so multiple UVB lights should be harmless, like if you just wanted to brighten the enclosure so that it is as bright as the day is outside. They probably won't even get the proper amount unless they baskbthe entire day what with leaves and plants blocking it