florescent tubes for UVB are quite effected, but they do have a limited range where UVB light is projected. Your dragon should be within 8-12" of the bulb. The bulbs also need to be replaced every 6-9 months. Though mercury vapor bulbs put out much more UVB than any existing florescent tube, there are some risks. Because of the higher amount of UVB they put out, MVB need to be at least 18" above your dragon's basking spot, or it could cause eye problems in your dragon, amoung other things. Also, MVB's have to be mounted completely vertical as they tend to burn out fast when mounted at an angle.



For some tanks, especially those that are 2' high or less with a closed top, mounting MVB presents a problem. To keep the 18" minimum distance, and given the fact the fixture for the MVB will take anywhere from 2"-4" off the total available height, you are left with a very low basking spot or using just the floor of the cage. This is especially true if loose substrate (ie washed play sand) is several inches thick. In a 2' high tank, you only have 6" to play with. Two inches of sand, plus a 3" thick light fixture (measuring from lip of the socket to bottom of the tank lid or top) leaves you with a 1" high basking spot. ALso remember dragons have some thickness to, so if the dragon is on the basking spot, his back may be at 18" or closer to the light of the bulb. I feel MVB should only be used with open top or screen top cages, so the bulb can be either mounted on the ceiling of the house, or suspended above the cage. Or, the cage should be over 2' high.
-----
PHLdyPayne

[ Show Entire Thread ]