It depends upon so many thaings, not least of which is the texture you are using!

A few more details will help us to understand your question better. For instance:

What are the settings for your spots? How many spots in the scene? What do the current results look like?
What kind of reflection are you looking for ie on glass, in a mirror, on water etc
What type of glow are you looking for ie a small glowing sphere or a whole character glowing?