UVB lightning option

Hi everyone
I am purchasing new uvb light for my 1 year old baby, I like Arcadia D3 dessert T5 12% UVB ,which has pretty good review online and not harmful to dragons eyes. I start to look into the detail of this product, and I notice that there are suggestive distance for the light which is 12"-18"(30-45cm) from light to beardie.
My tank has a basking spot 12'' to light(10'' from beardie to light). I have a mesh lid on top of tank and uvb light is going set on top of lid , the lid might block some uvb out, so I will get a light reflector fixure to stronger the uvb. I dont know exactly how much mesh lid gonna block out uvb and how much uvb reflector gonna inhance and I counld not find the right data to measure, I cant afford a solarmeter for right now. My concern is whether T5 12% UVB will be too strong to my baby after I put reflector on? or I just get a T8 12% UVB which need only 10-12"(25-30cm)distance which has lower risk of over exposure my babe on uvb?
Someone has experience please help me out with this set up situation, Its my first baby I want to give her the best. Thank you for reading! Ruby

You need to have basking decor 8-10 inches from UVB if sitting on top of screen - the screen will block out 30% of the rays -- if you decide to mount inside the tank it would need to be 12-15 inches from basking decor piece -- its easier to get the fixture mounted where you want and then move your decor pieces ---and you need a reflector and the decor piece needs to be directly underneath - the reflector would enhance the effectiveness of the UVB rays - if you dont use a reflector the distance is going to change and would need to be a lot closer---
Karrie

Hi Karrie
Thank you for the advise. I just got my new uvb light and have my husband help me to mount inside the tank.and I'll redo the basking spot, mke it lower.hope it turns out good..thanks..Ruby