During the Germination Phase, you should be checking for a sprout approximately every 24 hrs. Once you see some little bit of growth, skip to the Seedling phase of the grow. Here's how:

1: On the Vitals tab in the app, select Edit Current Grow

2: Next, select the Skip Current Phase option:

After this step, your grow lights will turn on using the normal day/night cycle of the grow recipe.