Akin to photoperiod seeds, the hydration of auto seeds will depend on where they are in their life cycle. Germination and seedling would require just 3 to 7 ounces of water every 4 to 7 days. Enter the vegetation phase; they'll need 10 to 20 ounces every 3 days and about 30 to 50 ounces during flowering every 2 to 3 days.