Stirring speed for yeast starter?

So I just scored a free stir plate, I work for a scientific distributor and one of my colleagues had an old stir plate collecting dust in his storage closet so he gave it to me. So I just made a starter and I have NO idea how fast I should be stirring it... Does it just need gentle agitation, or should it be stirred pretty vigorously so there is a vortex? Also, am I better off using a rubber stopper/airlock combo or just covering it with aluminum foil? Oh yeah, I don't have an Erlenmeyer flask (yet, I have two on order from my company for free as well ) so I'm using a 1/2 gallon glass carboy, hope this doesn't make a difference.

You may want to check this out:
http://maltosefalcons.com/tech/yeast-propagation-and-maintenance-principles-and-practices

You should also check out:

http://www.mrmalty.com/

You don't need to generatre a vortex. A gentle sirring is more than suffieicient. Use a foam stopper or foil, but no air lock or stopper. The objuective is to facilitate the gas exchange and to keep the yeat in suspension. That's basically it.

Niederhofer said:

You may want to check this out:
http://maltosefalcons.com/tech/yeast-propagation-and-maintenance-principles-and-practices

Click to expand...

That's an outstanding document, thanks.