UVB light distances

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UVB light distances

Postby MarvelousMarv » Sat Jan 12, 2019 7:28 am

I'd like to start by saying thanks to everyone who contributes and provides advice!!! I've learned so much and wish I found this site sooner!! Our little beardie Marv has been home for 2 weeks. He is about 7" and still settling in. He started to shed the last 2 days which is not helping on top of relocation stress. He's not eating as he should but we are trying everything and hoping post shed he'll feel better and his appetite will be back. I want to make sure lighting is correct to rule out any related issues and need some help.

I think I've got most of our setup in place now (no thanks to the starter kit and a million thanks to this site!!) I feel like I've moved things around in the tank 100 times to get it right lol!!

Our little one only seems to like his tree decoration, so I want to make the UVB work with this tree if possible. Marv never goes in or on his hide; we've moved it to the cool and warm sides with no luck. He goes on the tree to hide, bask and sleep. I get the feeling he is in no mood for us to mess with his tree!!

The tree is really tall though... low is 6.5" from the screen and the highest part is about 3" from the top.

Yesterday I got the Zoo Med T5 HO ReptiSun Terrarium Hood, 30-Inch. Instead of the coil UVB from the kit!!! Tube light is 22" in this one and has a reflector. We have a 36" tank.

Given how high the tree is and his usual basking spots...can I use the 5.0 bulb it came with?

Is 3-6" too close even with the 5.0 bulb or is it ok because it's weaker?

If it is ok, at this strength should it be on top of the mesh so it's not too strong? Or is unobstructed into the tank ok? I can do either.

I'm prepared to buy the 10.0 bulb but everything I've read seems to suggest the tree areas will be too close for that strength even on top of the mesh in a T5 fixture. Is that right?

I want to keep the tree he's comfortable in for now if possible as he was more stressed at first. I haven't added much else to the tank so he can settle in. I'm thinking as he grows I will get a lower/wider basking rock and move the tree out for a lower branch. Then a T5 10.0 seems to make sense.

Tank setup as follows:
40 gal with 2 part sliding screen lid
Basking light 100w Zoo Med Repti Basking Spot Lamp.
Hot side 90-95.
Cool side 78-80
Overnight about 70-72. No CHE.
Basking (lower end of the tree) at 105-110F.
Using IR Thermometer Gun.
Ceramic tile with a wood grain texture as flooring.

Thanks for the help!
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Re: UVB light distances

Postby Scion19801 » Sat Jan 12, 2019 8:38 am

everthing you have sounds good. being that youruvb tube is a 5.0 i'd make sure there is no screen between bulb and beardie. how close does your little one get from the uvb on average? i mainly use 10.0 and their out put is very low on the floor of my tanks which is 18" or so from the bulbs, so the 5.0 would be even less. but if you little one is mainly hanging out on the tree then all should be good.
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Re: UVB light distances

Postby kingofnobbys » Sat Jan 12, 2019 8:47 am


The T5ho 5%UVB tube in a reflector hood will give good levels of UVA & UVB at 6" , ie about 180 to 200 microW UVB / sq.cm at 6".

He will grow very quickly and will soon be bumping his head on the 5% UVB tube. So I'd suggest going to a T5ho 12%UVB tube and setting up his basking spot about 12" from the tube and perhaps removing the "tree".
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Re: UVB light distances

Postby MarvelousMarv » Sat Jan 12, 2019 10:44 am

Thank you both for the info!

He is 4-6" away from the UVB on average. I will put the light between the screen openings (no screen in the way) and ensure the top most part of the tree is out of range from the fixture. He already tried to jump for it once from the very top!

I will for sure plan to get a better, lower basking spot and log at 12" as he grows and then upgrade to the stronger bulb! At least I'll get some use out of the 5.0 even if it's only a few weeks.

Now to work on getting this little one to eat!!

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