Variables

Hello all!! Below are the variables for my back up ideas. I haven't listed all the ideas I had before because the more I thought about their variables, the more "holes" it had...In other words, I eliminated some ideas because they hurt my brain each time I thought about them,ok?
Oh and BTW I'm sure there's still plenty more variable for each idea...but here's what I have for now:

•Does the colour of a candle affect the rate at which it burns?
Dependent Variable(s): The rate at which the candles burn
Independent Variable(s): The colour of the candle
Controlled Variable(s): The place where I conduct the experiment (so the same temperature and atmosphere), the shape and size of the candles, the brand....

 •Do plants grow better with sunlight or artificial light?
Dependent Variable(s): Plants' growth (height, life span)
Independent Variable(s): The types of light (sunlight, incandescent light bulbs, Fluorescent bulbs, Metal-Halide and High-Pressure-Sodium etc)
Controlled Variable(s): the size pot for each plant, type of plant in each pot, type and amount of soil and fertilizer in each pot, the amount of water...


•Does the colour of water affect its evaporation rate?
Dependent Variable(s): The evaporation rate
Independent Variable(s): The colour of the water
Controlled Variable(s): the amount of water, the amount of food colouring put into it...

Okies...that's all for now...might have some more to add in about an hour or so...but till then, Ta Ta!!