Some "Light" Confusion- T5 or T10 UVB?

[Garrus]

I have obtained a 40 gallon breeder tank, and am in the proccess of setting it up... however, I have run into some confusion. When I look at the guides, I see the T10 UVB bulbs being recommended. However, on more recent posts in the same threads, I see T5 bulbs being recommended, along with the recommendation to simply mount said bulb on top of the enclosure, above the mesh, which the guides have told me was basically forbidden since the mesh cuts the light reaching the animal by up to 50%. So, which is the correct method? T10 inside the cage? Or T5 on top of the cage?

 

[CooperDragon]

What you're probably seeing is T5 and T8 which is two different sized bulbs and 5.0 vs 10.0 which are two different output levels. This can get pretty confusing at first. What you want for a 40g breeder is a T5 fixture and bulb with a 10.0 output instead of a 5.0. With Arcadia bulbs they use a percentage and it's a 12% output but still a T5. These can be mounted on top of the tank because they are more powerful than the older T8 bulbs.

I recommend this one http://www.lightyourreptiles.com/22-t-5-ho-fixture-high-output-with-arcadia-d3-12-ho-bulb/

Or this fixture https://www.amazon.com/Sunblaster-904296-NanoTech-Fixture-Reflector/dp/B00AKKUBDQ/
With this bulb https://www.amazon.com/Zoo-Med-26061-Reptisun-Fluorescent/dp/B00AQU8HAO