Lighting question

[futuredragonowner]

Hey everyone,
I've learned so much from reading this forum, everyone here is so well-informed and really cares for their pets. I hope to purchase my own bearded dragon soon, and I am working on getting its enclosure set up.
I purchased a Reptisun 10.0 tube T8 and the fixture for it and I have it installed inside the tank. It is attached to the back wall of the enclosure. I plan on purchasing a reflector for it. However, upon further reading I have found that most people say that the T8 is nothing compared to the T5, and that the T5 is what is needed. So, my question is: Is the T8 mounted inside of the tank with a reflector equivalent to the T5?
If it truly isn't enough and will cause my dragon to develop MBD, then I will absolutely switch to the T5. I plan on doing that sooner rather than later anyway. I just hate to have to exchange it if it isn't necessary to do so.
Thank you for your time and help!

 

[charmander16]

A T8 inside the tank, as long as it's within about 10" of the basking spot, will be fine.

 

[CooperDragon]

The T5 is superior in that it provides a much higher output and can reach longer distances. A T8 will work in a small tank but should be about 6-8'' above the basking spot even with a reflector. This will provide adequate UVB and prevent MBD if it's close enough but it is an older technology and not as powerful as a T5 would be.

 

[futuredragonowner]

My tank is a 40 gallon. Will it be good enough in that size tank?

 

[charmander16]

Yeah, I guess more detail is needed really.

A T8 can be fine, BUT, if you're using a T8 it should run the whole length of the tank. With a T8 you're probably going to be depending on all day exposure. With a T5, however, you do need to be concerned about too much UVB as well.

So if you have a 36" long tank, with a T8 you should be using a 34" bulb. If you use a T5 HO in a 36" tank you would likely only need a 18" bulb.

Some of this also depends on how far your basking spot is from the UV bulb as well.

Also, with the T5 inside the tank, you shouldn't have it any CLOSER than 12" from the basking spot, so it needs to be at least a foot away, whereas with the T8 the basking spot should be 7" to 10" away, with the rest of the tank being within 15" of the bulb.

Overall, IMO, a T8 is fine for a 40 gallon tank. Many 40 gallon tanks are only 18" high anyway.

 

[futuredragonowner]

Ah, the T8 I have is 24 inches. So I should probably just return it and get the T5?

 

[futuredragonowner]

But, since the T5 is so powerful, the basking spot will only be able to be about 6 inches off the ground since my tank is 18 inches tall. Won't it need to be able to get closer to the heat lamp, or is this incorrect?

 

[CooperDragon]

The main basking area should be about 6'' up but you can provide branches and other climbs that get a bit closer. If you go with a T8, you'll want the main basking area to be 12'' up so it's 6'' from the bulb. A T8 will work within an appropriate range but even then it provides mid morning levels of UVB vs the full daylight levels that a T5 provides.

 

[charmander16]

Actually, the best bulb for your situation is probably a Reptisun T5 5.0. The 5.0 isn't so powerful, it's between a T8 10.0 and T5 10.0.

Check this out: http://reptile-parrots.com/forums/showthread.php/9753-Zoo-Med-Reptisun-and-Powersun-UVB-test-results

https://zoomed.com/wp-content/uploads/ZM_Lighting_Selection.jpg

UVI of about 3-5 is good in the basking area. You don't want UVI over 8 for sure, but even 7 is pretty high.

 

[CooperDragon]

The 5.0 is another option to consider, I agree. It is a bit closer to a T8 than a T5 10.0 in terms of output but is a good middle ground and will provide brighter visible light which is nice to have. I usually suggest having a UVI between 3-7 over the main basking site with gradients down to 0 in other parts of the tank. Here are some test results from different combinations of lighting that show the output directly under the light as well as off to the sides. This helps give a good idea about the gradients you can provide with each light as well.

 

[futuredragonowner]

I may be wrong here, but going by the chart, wouldn't the T5 5.0 only be adequate in the basking area? Shouldn't the BD be exposed to UVB at all times?

 

[CooperDragon]

You want to create a gradient the way you do with heat. Intense UVB over the basking area and a gradient down to little or no UVB in other areas. This gives them choices so they can move about and get what they need at a given time. As long as there are areas of shade or low UVB then the focus should be on the intensity over the main basking site.

 

[futuredragonowner]

So the T5 10.0 would be too strong? Or is it an option?

 

[CooperDragon]

I'd consider it a good option as long as you provide shade and areas away from the bulb with lower UVB exposure so there are choices available.