Sufficient UV?

JoFisch

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Platinum Tortoise Club
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Dec 26, 2020
Messages
71
Location (City and/or State)
Washington
I have an Eastern Hermanns hatchling. I posted pictures of my set up on my introduction post
Thread 'Introductions'
https://www.tortoiseforum.org/threads/introductions.192856/
I supply UVB with a reptisun T8 10.0 tube. It is 48 inches long. Right now the enclosure is 3ft x 2ft so I have the tube light sitting diagonally across the enclosure. It is 12 inches above Opal’s shell. It has been in use for almost 2 months. I got worried that I don’t really know what the UV output is since it is a T8 bulb. It is on 12-13 hours per day but Opal usually goes into the hide or buries herself after about 9-10 hours, until the next morning.
I purchased a solarmeter 6.5r so I could see what the lamp was putting out. I’m worried it isn’t doing enough. The center of the tube is reading at 1.8-1.9. The ends are 1.1-1.2. I can’t lower the tube any further because of its length. Originally I was going to have a 4x4 ft enclosure but the breeder recommended starting smaller. Should I change to a different tube? When opal is a little bigger I plan on going to a 4x4 ft that will be covered by a plasic green house. Then increase to the adult sized pen later.
We’ll build an outdoor pen when Opal is big enough for warm months but we’ll always need a large indoor enclosure. If I’m going to purchase a new tube and fixture, I’d like to get something that will work for the current enclosure and the the bigger indoor enclosures.
Do I need to change my current tube? What length do you think would be best? I suppose I can use my current fixture in the adult enclosure since I should be able to drop it closer to the substrate if needed.
Thanks,
Joanna
 

zovick

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Nov 17, 2013
Messages
3,386
I have an Eastern Hermanns hatchling. I posted pictures of my set up on my introduction post
Thread 'Introductions'
https://www.tortoiseforum.org/threads/introductions.192856/
I supply UVB with a reptisun T8 10.0 tube. It is 48 inches long. Right now the enclosure is 3ft x 2ft so I have the tube light sitting diagonally across the enclosure. It is 12 inches above Opal’s shell. It has been in use for almost 2 months. I got worried that I don’t really know what the UV output is since it is a T8 bulb. It is on 12-13 hours per day but Opal usually goes into the hide or buries herself after about 9-10 hours, until the next morning.
I purchased a solarmeter 6.5r so I could see what the lamp was putting out. I’m worried it isn’t doing enough. The center of the tube is reading at 1.8-1.9. The ends are 1.1-1.2. I can’t lower the tube any further because of its length. Originally I was going to have a 4x4 ft enclosure but the breeder recommended starting smaller. Should I change to a different tube? When opal is a little bigger I plan on going to a 4x4 ft that will be covered by a plasic green house. Then increase to the adult sized pen later.
We’ll build an outdoor pen when Opal is big enough for warm months but we’ll always need a large indoor enclosure. If I’m going to purchase a new tube and fixture, I’d like to get something that will work for the current enclosure and the the bigger indoor enclosures.
Do I need to change my current tube? What length do you think would be best? I suppose I can use my current fixture in the adult enclosure since I should be able to drop it closer to the substrate if needed.
Thanks,
Joanna
I would recommend getting a T5 tube. They are much stronger than the T8's and will provide better UVB for your tortoise. You will need a different fixture for the T5 as the bulbs are smaller in diameter than the T8's, so the pins won't fit in the T8 fixture. You might get all the output you need with a 2' T5 but you could try the 4' length if you wanted to do so.

Since you have the Solarmeter 6.5 already you will be all set to get the correct UVB reading by adjusting the height of the new fixture. I would recommend trying for a reading of about 3.0 or 3.2 near the center of the tube.
 

ZenHerper

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Joined
Feb 27, 2020
Messages
2,078
Location (City and/or State)
New Jersey
The issue with moving the fixture too close to the ground becomes one of over-exposing the corneas to uvb radiation. Those brow bumps shade the eye surface from direct sunlight. If direct light beams are aimed under the brows, the eyes can be damaged in a number of ways.

Two options: opt for a stronger bulb type, or write this bulb off as a dud and replace it with a fresh one. People do often find that the T8s are not quite up to snuff.
 

JoFisch

Member
Platinum Tortoise Club
Joined
Dec 26, 2020
Messages
71
Location (City and/or State)
Washington
Thanks for your help. If I get the T5 tube and raise it so that there is a reading of 3-3.2, would I still keep it on for 12 hours? I think I read that the HO tubes can emit in the 5-7 range so if that were the case you’d only have it on for a few hours mid day. Any idea how high the tube would typically be placed to get in the 3 range? I know my solarmeter will be the best way to tell but if I am likely to have to raise it over 20-22 inches above the substrate, I’ll nee to rethink my enclosure top.
Thanks
 

zovick

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10 Year Member!
Joined
Nov 17, 2013
Messages
3,386
Thanks for your help. If I get the T5 tube and raise it so that there is a reading of 3-3.2, would I still keep it on for 12 hours? I think I read that the HO tubes can emit in the 5-7 range so if that were the case you’d only have it on for a few hours mid day. Any idea how high the tube would typically be placed to get in the 3 range? I know my solarmeter will be the best way to tell but if I am likely to have to raise it over 20-22 inches above the substrate, I’ll nee to rethink my enclosure top.
Thanks
It is just a guesstimate, but I think that you will get the 3.0 to 3.2 reading with a T5 bulb placed 12" to 16" above the substrate.

I used fixtures which held 3 four foot T5 bulbs and had them mounted 16" above the substrate which gave me a reading of about 4.5 for my adult Radiated Tortoises.

Contrary to what some others on this forum do, I kept my T5 bulbs on for 14 hours daily. If the tortoises didn't want to stay under them, there were always shaded places provided for them use to get out of the "sun".
 

Tom

The Dog Trainer
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Location (City and/or State)
Southern California
I have an Eastern Hermanns hatchling. I posted pictures of my set up on my introduction post
Thread 'Introductions'
https://www.tortoiseforum.org/threads/introductions.192856/
I supply UVB with a reptisun T8 10.0 tube. It is 48 inches long. Right now the enclosure is 3ft x 2ft so I have the tube light sitting diagonally across the enclosure. It is 12 inches above Opal’s shell. It has been in use for almost 2 months. I got worried that I don’t really know what the UV output is since it is a T8 bulb. It is on 12-13 hours per day but Opal usually goes into the hide or buries herself after about 9-10 hours, until the next morning.
I purchased a solarmeter 6.5r so I could see what the lamp was putting out. I’m worried it isn’t doing enough. The center of the tube is reading at 1.8-1.9. The ends are 1.1-1.2. I can’t lower the tube any further because of its length. Originally I was going to have a 4x4 ft enclosure but the breeder recommended starting smaller. Should I change to a different tube? When opal is a little bigger I plan on going to a 4x4 ft that will be covered by a plasic green house. Then increase to the adult sized pen later.
We’ll build an outdoor pen when Opal is big enough for warm months but we’ll always need a large indoor enclosure. If I’m going to purchase a new tube and fixture, I’d like to get something that will work for the current enclosure and the the bigger indoor enclosures.
Do I need to change my current tube? What length do you think would be best? I suppose I can use my current fixture in the adult enclosure since I should be able to drop it closer to the substrate if needed.
Thanks,
Joanna
I think your tortoise will be fine with a UVI of 1.8-1.9 left on all day. Mine were fine with 1.1. Use a calcium supplement with D3 over the winter, and get some real sunshine in the warmer months. Mazuri as a supplemental food will also provide some D3.

There is no reason you can't also use the T5 bulb that Zovick suggested. It won't hurt anything, but its not "necessary" in my experience.
 
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