Fermentation temp??

Hi,
My first batch started to bubble like crazy after only about 18 hours. I hope that is a good sign. My question is this: I have my glass carboy in my basement in the unfinished part and the temp is reading about 67-68 degrees. Is this too cool?? At night, when it probably gets cooler than that, do you think I should move my electric space heater closer to the wort and put it on overnight to keep the temp up closer to 72??? Or, is the fact that it started to ferment so quickly suggest it's fine and I'm worrying for nothing?

It's probably perfect- but it really depends on the yeast you are using. Some ferment better at cooler temperatures, some at slightly warmer temperatures. What yeast did you use?

Ideally, ales ferment at the temperature you have it at, no warmer.

Lorena