1. Welcome! Are you interested in tortoises? If so, we invite you to join our community! Our community is the #1 place for tortoise keepers to talk online. Once you join you'll be able to post messages, upload pictures of your tortoise and enclosure, and discuss any tortoise topic with other tortoise keepers. Get started today!

Changed UV light to Reptisun T8 10.0, 13” distance ok?

Discussion in 'North American Tortoises (genus Gopherus)' started by MoreCowbellAz, Oct 12, 2019 at 4:27 PM.

Help Support Tortoise Forums by donating:

  1. MoreCowbellAz

    MoreCowbellAz New Member

    Joined:
    Sep 19, 2019
    Messages:
    21
    Likes Received:
    3
    Trophy Points:
    3
    Location (City and/or State):
    Phoenix, Az
    Still tweaking my baby DT enclosure, I just converted from a MVB to the above mentioned 24” tube type UVB, and to start I set it at 13” from the substrate, so figure 12” from light to shell. Does that seem about right? I see some conflicting info, their quick lighting facts sheet says 10”-18”, while their color coded chart on the web site suggests something a little closer like 8”-12” for mostly full sun animals. I don’t want to overdo it, esp since he’s so small, but I also Don’t want to defeat the whole purpose of getting him some extra UVB.

    He’s got a basking bulb on the warm end of the enclosure, so heat is covered.
  2. MoreCowbellAz

    MoreCowbellAz New Member

    Joined:
    Sep 19, 2019
    Messages:
    21
    Likes Received:
    3
    Trophy Points:
    3
    Location (City and/or State):
    Phoenix, Az
    (These ads do not appear for registered members.)
    Also, I was planning on ordering a UV meter and it occurred to me, even if I had one I don’t know what reading I should be going for. I see a lot of recommendations to get a UV and avoid the guess work, which I like, but I’ve not seem much about what numbers are good, especially for. DT. The Zoomed site says 1 to 2.6, but that seems low from the little bit I’ve been able to find.

    Can anyone tell me what UVI numbers I should be going for? I assume once I have a good target then I can dial the height in.
    Tom likes this.
  3. Markw84

    Markw84 Well-Known Member 5 Year Member Platinum Tortoise Club

    Joined:
    Jan 17, 2012
    Messages:
    3,341
    Likes Received:
    5,149
    Trophy Points:
    113
    Location (City and/or State):
    Sacramento, CA (Central Valley)
    I know most people seem to hate the answer and balk at cost, but a UV meter - solarmeter 6.5 = is really the only way to tell. Even individual bulbs can vary depending upon the type and quality of fixture they are put in, so just saying a T8 10.0 is often not enough!.

    If you keep the UVB light on all day, I would say a reading of 2 is good. I use a reading of 3.5 - 4.0 for my tortoises, but only have the UVB light on for about 6 hours midday. Watch your tortoise for basking habits. An incadescent bulb providing heat should be right next to the peak UVB zone as heat encourages basking along with brighter light. Some tortoises tend to be morning baskers, using the sun to heat up and start their metabolism and avoid the heat and high UV levels of midday. Desert Tortoises often follow this pattern. IF so, perhaps a UVI of 4.0 and on from 8AM to 1 PM would be a good goal.
    Tom likes this.
  4. Tom

    Tom The Dog Trainer 5 Year Member Platinum Tortoise Club

    Joined:
    Jan 9, 2010
    Messages:
    45,578
    Likes Received:
    25,488
    Trophy Points:
    113
    Location (City and/or State):
    Southern California
    In my experience with that particular bulb, it needs to be no more than 9-10 inches away to get a reading of 1-2 on the UVI from a Solarmeter 6.5. They don't make a lot of UV, so they are pretty safe and you don't have to worry about overdoing it. I also found that after 3 years of continuous use for 12-13 hours a day, both of my bulbs were still making the same UV levels as when they were new. Glad I didn't replace them every six months like some people do.

    As Mark said every bulb coming out of the factory can vary, and different batches do vary. The fixture also makes them vary, so a meter is essential to know what is going on over your tortoise. When you get your meter, take measurements and come back and share so we can all learn.

    I like a reading of 5-7 and only run my bulbs for 3-4 hours mid day. I use the Arcadia 12% HO type. A wide variety of strategies can work, and different people have different views on this matter.
  5. Sterant

    Sterant Well-Known Member Platinum Tortoise Club Tortoise Club

    Joined:
    Mar 6, 2016
    Messages:
    521
    Likes Received:
    638
    Trophy Points:
    93
    Location (City and/or State):
    Albany, NY
    Also keep in mind that the reflector in your fixture matters. A high quality polished aluminum reflector can nearly double the downward UVB as compared to no reflector or a junk one. I run T5 HO bulbs (reptisun 10.0). I try for a reading of 5 - 7 for adults and can get it with the fixture about 18" above the substrate. These bulbs can also last 3 years.
Similar Threads: Changed light
Forum Title Date
North American Tortoises (genus Gopherus) New Mojave tortoise owner, do I hibernate, keep outdoors/UVB light indoor? Help Nov 14, 2018

Share This Page