[Keegan]

Is there a seed mixture that works better in the early to mid spring? More rye?

 

[RigglePLC]

A top-quality rye like "Amazing" would be a good bit faster. If you are in a real big hurry-you might consider pregerminating the seed in warm water inside. Not sure about the details, but I think you also have to bubble air through the water to help carry off the carbon dioxide. Maybe your hot tub isn't busy.