Wally,
I'm not sure why Byron discards his first cup of tea, but I just steep a bag in a large mug until it's cool and fairly strong. Then I keep it in a jar in the fridge and add a little of it(1/4 cup?)to a large spray bottle of water and use that to water my seedlings. The only damp off I've had is when I switched to a watering can and splooshed way too much water into a few cells and I hadn't added the tea.
So I'm guessing...1/4 cup of tea to a quart of water? I have just been winging it, but it seems to have worked. I hope you get more feedback on this.