UVB light type &positioning for a bearded dragon

Question
QUESTION: Hi,

No pun intended but I'm hoping you can shed some light on this for me.

I'm currently looking to set up a vivarium ready for its bearded dragon occupant and want to make sure I've got all the fittings right and tested to the right temperatures etc before I purchase it's dragon occupant.

I currently have a vivarium - 4ftx2ftx2ft and am unsure of exactly how the UVB should be set up within it. I've read a number of sites and keep getting mixed answers on which UVB tube would be best, where the best position is in the vivarium for maximum exposure etc so - here is my current information, could you tell me if this is right or wrong - the health of my future beardy is the MOST important thing to  me!! -

I've hard that repti-glo 8.0 can give enough UVB for a bearded dragon, though because of the 10"-12" range on the light this should be positioned about half way down in the viv (spesh of this height) to ensure the beardy gets within the right distance of the UVB for it to have the greatest effect - for a 4ft (48") tank the best length would be 42" to account for fittings and electronics - is this correct? (And that the repti-glo 10.0 should not currently be used as it hasn't been sufficiently tested to ensure it is safe?)

OR - I've heard the repti-sun 10.0 is an excellent source of UVB and would provide plenty of UVB for the lizard at up to 20" height - and therefore could be positioned at the top of the vivarium - however the greatest length i sonly 36"?

The vivarium does not have a screen so none of the UVB for either of these tubes would be filtered before it got to the lizard.

Can you advise me of the best set up of these?

ANSWER: Hello Kat,
Personally, for a 4x2x2, I would recommend the Reptisun 10 flourescent tube bulb over the Reptiglo 8 tube bulb, OR a mercury vapor bulb such as the Megaray or the T-rex active UV heat.
Correct, until further testing is done, do not use the Reptiglo 10 tube or coil, it is not a good light.

It isn't necessary for a flourescent tube UVB to take up the entire length of your tank.  I would go for a 36 inch that is sufficient.  

Technically they will put out UVB at 20 inches, but ideally, they should be 6-8 inches for maximal effect.  I feel 20 inches is too far personally.  It is great you will not have a screen to filter the UVB out at all.  Very good.

You should consider a mercury vapor bulb, they work well in those sized tanks.  

If you would like me to send you some UVB links so you can see the emissions, I can, just let me know!

Tracie

---------- FOLLOW-UP ----------

QUESTION: Thnaks tracie thats really useful and does agree with the research I'd already looked at - would yuo therefore suggest (I'm assuming you ment to write repti-sun 10 flourescent in your first sentance) that this would be best suspended at about half way height along the back wall of the viv for max effect?

I'd love to take a look at those UVB links as well if possible - thanks for your help!

In addition (and un-light-erlated question) in your opinion and experience - what is the best substrate for a bearded dragon. This is another area that has been extremely controversial during the research - one thing everyone seems to agree on is that calci-sand is a complete no no due to the risk of impaction.

However others suggest play sand is safe, paper is best for a baby....paper shuold never be used...play sand is bad etc. It's difficult to sort out the good information from the bad - so again, would love to know what substrate you've found to be most successful (and safe) for yuor beardies!  

Answer
Hello Kat,

Great glad I could help.  Yes, the Reptisun 10 would be best mounted either along the back of the tank or the middle, wherever you plan on putting your basking light you will need to place the Reptisun 10 directly beside it.
Here is the link to show you how much emissions the Reptisun 10 & the Reptiglo 8 flourescent tube bulbs put out:

http://www.uvguide.co.uk/fluorescenttuberesults.htm

That is the main one that has emissions, & there is tons of other information on there also.  

Yes, substrate is a very controversial issue among breeders & keepers.  Calcium based sand is not a good product, no matter what brand it is.  Being calcium based, it can encourage the reptile to lick it especially if they happen to be calcium deficient.  This type of sand hardens like cement when it gets wet which makes it extremely dangerous when it gets into the GI tract.  It can cause fatal impactions.  Though some claim they have never had problems while others have had awful problems & even lost their dragons due to it.  
Washed & sifted playsand is the better choice.  I would not put them on sand until they are at least 1 year.  The other choices are non adhesive shelf liner, paper towels, reptile carpet or tiles.  
We have used the rubberized flooring for ours.  

Tracie