OK, i'll start by saying i know next to nothing about electronics, but i reckon this should in theory be a fairly simple hack.
I Have a Baby BiOrb fish tank with 2 goldfish in. the tank is great, if a little small, and the lighting unit on the top of the tank is quite bright. i guess they use the same light unit in the small tanks as the large ones, so although its probably fine in the large tanks it's quite bright in a small one. i get the impression the fish don't like it too much as they spazz out a bit when its switched on.
what i want to do is to replace the standard bulb with a less bright LED so that the lighting is more ambient and more comfortable for the fish. i've seen the moonlight ideas on here using blue LEDs which look really nice, however these tutorials are for building a setup from scratch and not for replacing components in an existing setup.
the question is, what would i have to do to replace the bulb with an LED? the existing light is powered from a 12v plug which also powers the air pump; theres a central power box with two cables coming off, one for the light and one for the pump, so i guess its a parallel connection meaning theres a full 12v to play with for the light. would i need to add extra resistors or something like that, or is there such a thing as a 12v LED? what about several LEDs?
(EDIT) - official literature says that the bulbs are 5w halogen bulbs.
another option would be to add LEDs as a secondary light, maybe with a secondary switch for separate control to the main light. would this be easier at all?
any knowledgable advice would be a great help as i've no idea where to start.