Reptisun T8 vs T5 in new enclosure

[apndi]

I currently have my BD in a 36” L x 16” W x 18.5” H (about 40 gal) tank with a reptisun 10.0 T8 UVB tube. I have the tube mounted inside the tank along the top part of the back wall with command strips and an under-cabinet fluorescent light fixture (I removed the plastic that would’ve covered the bulb). He sits about 8” away from it and I’ve never had any problems with it. I’m soon upgrading him to a 48” L x 24” W x 20” H and was wondering if I should upgrade him to a reptisun 10.0 T5 HO UVB tube mounted on top of the screen with a reflector fixture in the new enclosure. I’m planning on building a basking platform about 10” away from the screen to prevent heating problems (I’ve really struggled with getting him close enough to the top in his current tank and getting temps that are too cool). Is 10” away too close for a T5 HO bulb in a reflector fixture on top of the screen (the screen has pretty large holes but I forgot the sizes)? Should I move the platform down 2 inches so he’ll be 12” away instead? Or can I keep it at 10” and stick with my T8 mounted directly inside the tank on the wall above the platform? The only problem is that he might be able to touch it if he stands on his hind legs (currently it’s on the other side of the tank from him; in the new tank it would be along the same wall as his basking platform). Any insight would be appreciated, thanks!

 

[CooperDragon]

I would definitely upgrade to a T5. They provide better output than the T8 at safe distances. 10'' is about right for a T5 in a reflector fixture. The fineness of the mesh top has a lot to do with how much is intercepted though. 12'' is about right without a mesh top in the way so I'd estimate 10'' is good for most cases. The lights create gradients as you move away from them (which is good) so I wouldn't worry about too much UVB if there are other easily accessible areas with lower UVB.

 

[Mellowmalt]

t5's are far more efficient than t8's so if you are thinking about it, get the t5.
However placing the light above the screen will reduce it's efficiency by 40% and you are better using the t8 inside.
Doesn't matter if the BD can touch it occasionally, just hang it high enough that he can't break it.

 

[apndi]

I would definitely upgrade to a T5. They provide better output than the T8 at safe distances. 10'' is about right for a T5 in a reflector fixture. The fineness of the mesh top has a lot to do with how much is intercepted though. 12'' is about right without a mesh top in the way so I'd estimate 10'' is good for most cases. The lights create gradients as you move away from them (which is good) so I wouldn't worry about too much UVB if there are other easily accessible areas with lower UVB.

If I got the T5 I would get the 22" that can fit into a 24" fixture. So it would only stretch half the length of the cage. I was planning on putting a lower wattage bulb on the cool side because of the longer cage length so he wouldn't have to choose between basking temp and room temp. Would that provide enough of a gradient?

 

[apndi]

t5's are far more efficient than t8's so if you are thinking about it, get the t5.
However placing the light above the screen will reduce it's efficiency by 40% and you are better using the t8 inside.
Doesn't matter if the BD can touch it occasionally, just hang it high enough that he can't break it.

Part of the reason I was wanting the T5 to put above the mesh is because the new viv is wood and I wasn't sure how well the command strips would stick to it. I suppose I could try zip tying the T8 fluorescent fixture to the mesh; I think the holes are big enough for that. That would put it at about 8" like it is now. Would that be okay? I thought using the T8 was fine but then I read a thread about how only the T5 is good enough so now I'm unsure.

 

[CooperDragon]

T8 has lower UVB output. It needs to be about 6-8'' away to be useful but you'll get much better output with the T5 at 10-12'' so I advise moving to that.

 

[Drache613]

Moved by Moderator from General to Enclosures

 

[apndi]

Cool, thanks everyone!

 

[apndi]

I have another question. Like I said before, I was going to build a basking shelf 10” away from the hood and have the T5 and the basking bulb 10” above him on the screen. The new viv is coming along but unfortunately when I came home from work yesterday my dad had put a 4 in wide center beam across the top, so that there’s only 22” of space for the UVB bulb. The fixture is 24” long. He didn’t understand that I was going to put the UVB on the top. Would it be okay if I put the UVB diagonally across the top? That means that only a little bit of it would directly hit the basking platform and the rest of it would be over the rest of the cage, 20” away from the floor (the cage is 20” tall). Is that not enough? My only other option is to have it straight across like I had planned but 2” of it will be covered by the center wood piece. Would that be safe for the bulb to touch the wood? I know it doesn’t get that hot. And then it would only be 20” of UVB bulb (since the bulb itself is 22” but I guess that’s not that big of a deal. Any input would be appreciated.

 

[CooperDragon]

Yeah that should be fine. The UVB light casts a beam outward so the highest UVB is directly below the bulb but there is effective UVB to the sides as well. If you put it at a diagonal, you could put the basking light in the center of what would form a triangle with the side and back of the tank. That should provide a pretty good basking area.

 

[apndi]

Okay thank you, I will try putting it on the screen diagonally!