tubing size for Speidel 30L Fermenter

I just bought a new speidel 30L fermenter from morebeer.com.

I dipped a plastic baggie in star san and used a rubber band to surround the sanitized spigot at the bottom of the speidel.

This is going to be a fruit beer so my question is in regards to transfer using the spigot to secondary.

What is the best tubing to transfer this without adding air to the line.
Some threads I have read say that one size is to big and another is too small.
I dont want to add any air in the line.

thoughts??

 

For those that may search in the future. Here is the reply from morebeer customer service.

Thank you for your question. 1/2" ID tubing fits nicely on the spigot with a tight seal. Please let us know if you have any other questions or concerns.

Thank you,
Keith Klingler
Customer Service Manager
MoreFlavor! Inc
1-800-600-0033