1. It depends on what type of enclosure you have, as well as size and other heat sources. I have a 40 gallon fish tank with a heat resistant mesh screen on the top. I use a heat mat on the bottom of the cage under one hide and a 75W bulb on the middle of the top. I also have a 60W night bulb so I can observe him while hes active at night, as well as let him be able to bask at his leisure. If your house is kept comfortably warm in the winter then you should not have to get special 'winter' bulbs, meaning a higher wattage to compensate for the cold air during the season. Also, make sure your lamp states that it is suitable for the type of Wattage you will be using. 2 . A ceramic heat emitter looks somewhat like a light bulb, however does not produce any light. It only gives off heat. 3. A mercury-vapor lamp is a gas discharge lamp that uses an electric arc through vaporized mercury to produce light. The arc discharge is generally confined to a small fused quartz arc tube mounted within a larger borosilicate glass bulb. The outer bulb may be clear or coated with a phosphor; in either case, the outer bulb provides thermal insulation, protection from the ultraviolet radiation the light produces, and a convenient mounting for the fused quartz arc tube. Mercury vapor lamps are more energy efficient than incandescent and most fluorescent lights, with luminous efficacies of 35 to 65 lumens/watt. Their other advantages are a long bulb lifetime in the range of 24,000 hours and a high intensity, clear white light output. For these reasons, they are used for large area overhead lighting, such as in factories, warehouses, and sports arenas as well as for streetlights. Clear mercury lamps produce white light with a bluish-green tint due to mercury's combination of spectral lines. This is not flattering to human skin color, so such lamps are typically not used in retail stores. "Color corrected" mercury bulbs overcome this problem with a phosphor on the inside of the outer bulb that emits white light. They offer better color rendition than the more efficient high or low-pressure sodium vapor lamps.

While you can use a house light, I highly discourage it. House lights are made for giving lots of light, not heat, so they won't be that affecting for basking. Also, they don't give off any UVB at all, which is essential for turtles to fight against Metabolic Bone Disease! I'd recommend a Zoo Med Reptisun 10.0 or 5.0 for that.

This light is for heat only. When you have reptiles they always need a UVB light along with this. I would also suggest letting them in natural sunlight for a while during a hot, sunny day.

These fit into any lamp but due to the heat it give off it should only be used with a ceramic lamp that is specifically made for heat bulbs.