Hi dannylomb
I want to commend you on doing homework and asking lots of questions!
I would not recommend placing any light fittings/bulbs inside the chameleon’s cage - that includes heat emitters and wire frames. This will for one, limit you in terms of misting inside the cage. I would place the basking lamp on the outside, at a sufficient distance from the cage, for the sake of the chameleon. The heat emitted by basking lamps are concentrated in the centre (like a magnifying glass) and I have seen too many chameleons with horrible burns – even from concerned and caring keepers. Take any precautions necessary to avoid this!!! Place your basking lamp at a safe distance - measure the temperature on top of your flexarium where the heat from the lamp is concentrated. If you can hold your hand in this spot on top of the screen for 2-3 minutes and not feel pain, it is safe to mount your basking lamp at that distance. Make sure you provide a perch close to the top screen inside the cage (far enough away from the top screen for your chameleon to comfortably fit between its perch and the top screen) and use a thermometer with the probe on the spot/perch where the chameleon will be basking. This way it can get itself as close as possible to the heat source, without getting burnt. Many chameleons like to hang upside down from the top screen to bask - and many get burned this way if the heat source is too close. It is worth mentioning that your basking lamp might work great today in 25ºC weather, but tomorrow, at 34ºC outside, it is suddenly a lot hotter in the same spot. A thermostat is always a good investment!
Notes on basking lamps and fittings:
By mounting your fitting to something other than your flexarium, it is easy to move the flexarium outside without having to disconnect any wires etc.
I can recommend Exo Terra’s Sun Glo Halogen Neodymium lamp as a basking lamp (it emits UVA in addition to heat and visual light).
UVB bulbs can be placed directly on top of the screen, since they do not emit enough heat to cause the type of burns mentioned above. I have no experience with UV burns, but will take Chamsss advice to heart. If your chameleon’s perch is close enough to the top, it will most certainly use the opportunity to absorb whatever heat it can from the UV light, so you should not have to worry about UV depth. Replace your UV bulbs every six months to ensure proper UV exposure.
Here’s a useful link to Exo Terra’s Reptile Lighting Guide:
http://www.exo-terra.com/en/explore/guides.phpYour chameleon needs a night time drop in temperature for optimum health and should not need a heat source at night. It will also need a overall temperature drop during winter. If you want to provide some additional heat during winter nights, I would recommend that you heat the room where the chameleon is kept, and put the heather (wall-mounted ones work well) on a thermostat. There is a new wall-mounted heather for sale that has a built-in thermostat.
I have observed more than one of my chameleons traveling down to the pots of their plants, shooting at a piece of motionless bark, chewing on it and swallowing some, despite my best attempts to get it out of their mouths. My chameleons haven’t had any impaction issues - touch wood - but I would not recommend a substrate consisting of bite-sized pieces