Use 5ml per 1 liter of water for rooting clones and young seedlings.
Older seeds have a better chance of sprouting when they are soaked in Humic Acid Plus for 3-6 hours before planting.
Soak your rooting media prior to planting. Just make sure you don't drown your plants by removing excess water.
All other - 1-2ml per 1 liter of water
Humic Acid Plus is a natural, organic plant aid that can be fed with every watering without concern of overdosing.