Posted: Mon Jan 29, 2007 2:31 pm
Yeah, the lighting thing is somewhat complicated. You are a VERY WISE person to be thinking through all these things BEFORE you get your turtle! GOOD THINKING!
You do have to get two lights UNLESS you have a big tank (55 gallons or more) in which case you can do it with just one bulb.
(1). For a two light setup you need one bulb for UVB which will also provide UVA and one for heat. Both bulbs have to be shining directly on the basking area.
(a) The UVB/UVA bulb can be a tube flourescent or a compact flourescent. Incandescent bulbs don't provide UVB. The package that the bulb comes in must specify the amount of UVB provided (like 5.0 or 10%, for example). If the package doesn't give an amount, then the amount is too small to do your turtle any good. You have to get these bulbs at a pet store or on-line from a pet supply place. Because the UVB from these bulbs is actually rather weak, you don't want to block any significant amount of it with a screen. You can set a long flourescent tube fixture on top of the unscreened tank, or you can use a clamp fixture for a compact bulb. There are a lot of other ways to handle the setup. If for some reason you need to use a screen, just be sure it have really big holes in it - like 1/2 inch or bigger - so as not to filter out the UVB. Don't put a glass cover between the bulb and the turtle. The UVB output from a bulb will decline fairly rapidly so it will have to be replaced after around 6 months, even if it still lights up.
(b) The heat bulb will be incandescent and can be a regular household bulb, like a 60 watt bulb. You can also get incandescent bulbs at the pet store that will provide significant UVA in addition to heat and light but since you're already getting that with the flourescent bulb I don't see the point. The heat bulb can go in a clamp fixture. You'll position the bulb so it heats the basking area to around 88 or 90 degrees. It is very important that this bulb not be too close to the turtle because if the turtle touches it, he will get burned, or if cool water drops hit it, it will explode since it is hot. An alternative to an incandescent bulb is a ceramic heat emitter which is shatterproof since it isn't made of glass!
(2) If you have a large tank (55 gallons and up) you can use one bulb - a mercury vapor bulb (MVB). You would use a 100 watt flood light (be sure not to get a "spot" light by mistake as it would be much too strong). An MVB provides heat, UVA, UVB and light. It's expensive but it lasts longer than a UVB flourescent so will cost about the same over time. It gets very hot so has to be in a ceramic fixture. You can use a clamp fixture or some sort of hanging fixture. Be careful positioning it that the basking area doesn't get TOO hot. Also, it can shatter like an incandescent bulb which is another reason to be sure not to get it too close. It has to be close enough, though, that your turtle gets enough UVB. Somewhere between 12" and 14" from the basking turtle's back will probably get you what you need.
Whew! Does this help?
Last edited by
SpotsMama on Mon Jan 29, 2007 6:10 pm, edited 1 time in total.
SpotsMama
