Lighting question

[joannas11]

Hi,
I am hoping to get a tortoise in the next few weeks and have been trying to wrap my head round the lighting and heating requirements. I have ordered a 6ft tortoise table and I think I will go for a UV light strip in the middle of the table and separate heat lamp at one end. I have read the info about temperature etc so I think I get that. My question is - what length bulb should I be going for for the UV strip, based on the size of the table? The bulb will be suspended overhead using brackets, rather than attached to the side and I will use reflectors.
This bulb https://www.reptiles.swelluk.com/arcadia-d3-reptile-lamp-t8-12-uvb comes in 5 different sizes.
Thank you in advance for your help.

 

[Markw84]

Welcome to the forum. You have found the best place for tortoise information!

I would not recommend getting the T8 size bulb. For tortoises, I much prefer the T5 HO bulbs. The put out more UVB and as a result can be mounted higher to give the same UVI level. That allows for a much more even distribution of the proper UVI level over a greater area. Additionally, with the weaker UV producing bulbs, you would have to mount closer and get a much more dramatic change in UVI levels in a very small difference of distance. Much less margin for error. Here is the complete fixture and bulb I recommend and use in all my enclosures from your same supplier you linked:

Arcadia Pro T5 UVB Kit - Desert 12%

Highly adaptable lighting kit producing UV-rich light Links up to multiple kits Fix inside a vivarium or place upon a wire mesh glass terrarium

www.reptiles.swelluk.com

I like to have the UV fixture about 1/3 the length of the entire enclosure. I place it more to one end to have the other end a more "shade level" area away from the UV. I mount an incandescent bulb of perhaps 75 watts next to the UVB strip to give the basking zone both the UVI level along with the warmer color light and heat of the incandescent.

A tortoise needs good bright light over its enclosure. Days should feel like daytime outdoors! You will then need some additional Ambient lighting. I use LED bulbs or strips for this. I would get enough to have about 3000 - 4000 total lumen over the enclosure. Get some LEDs with good color rendering and in the 5000k color range.

I have all 3 of these lighting elements on their own automatic timers. I set the basking light (incandescent) to be on for 14 hours each day. The ambient LEDs are on for 13 hours (on 1/2 hour after basking comes on and off 1/2 hour before basking goes off). I have the UVB light on about 4 hours midday.

Next provide some nice plants in pots that can hang over the edges of the pots to create good natural hides and shade gradients. About 2/3 of my enclosures are covered in plants to create the type of place a tortoise would naturally seek out in the wild. Tortoises do not live, nor feel comfortable in barren areas.

Last be sure you have a heat source to maintain your minimum ambient temperature. That should be on a thermostat and provide heat with no light. nights need to be dark. You never stated the species, so that will determine proper heating levels.

 

[joannas11]

Thank you so much - this is so helpful and really clarifies things for me.

It is a Horsfield's tortoise I am planning to get; sorry I didn't mention that.

I have a possibly silly follow-up question - you mentioned ambient light from LEDs. Would just having the lights in the room on have the same effect? The table will be in my kitchen and we have ceiling lights, skylight windows and the table will also be next to our french doors and another window on the side, so there will be a fair amount of natural light in the middle of the day and I can put the lights on in the mornings and evenings when its a bit dimmer or even all day. Would I still need LEDs?

Thank you!

 

[Markw84]

Thank you so much - this is so helpful and really clarifies things for me.

It is a Horsfield's tortoise I am planning to get; sorry I didn't mention that.

I have a possibly silly follow-up question - you mentioned ambient light from LEDs. Would just having the lights in the room on have the same effect? The table will be in my kitchen and we have ceiling lights, skylight windows and the table will also be next to our french doors and another window on the side, so there will be a fair amount of natural light in the middle of the day and I can put the lights on in the mornings and evenings when its a bit dimmer or even all day. Would I still need LEDs?

Thank you!

Not silly at all. I personally believe most people underlight a tortoise enclosure. Light is a vital an important part of how tortoises regulate their activity and daily and annual rhythms. The live by daylight, not artificial indoor lighiting. So I believe it valuable to better emulate a brighter, daylight type environment, and then provide ample shade gradients. I find tortoises act much differently when put in that type environment and are much healthier.

Ambient lighting in a room may seem bright, but it is nowhere near as bright as outdoors. Additionally, light intensity diminishes geometrically with distance. So a 1000 lumen light ( a good 12-15 watt LED blub) on the ceiling of your kitchen is far different than that same bulb 20" or so above the enclosure substrate. For example a 1000 lumen led light will produce about 6500 lux at 2 feet away, but at 5 feet away it is only 1030 lux. So the same light is over 6 times brighter 2 feet above substrate as opposed to coming from a light mounted on your kitchen 8 ft ceiling.

So - I would certainly recommend adding some ambient lighting to the enclosure itself.