Googling bmx chain tension brings up more results. Some people are saying they like a 1/2" of "sag" in their chain. Actually one guy said that.

The consensus seems to be 1/2" total up and down movement.

Another good one someone said is if you throw your cranks backwards and it freewheels for at least 1 rev before stopping you are good. If it stops before, it's too tight.

Thanks. Guess I will tighten it up a tad.