Hello there Drumsnbuds,
Using hydrogen peroxide on your marijuana plants will not bring them harm. Peroxide helps aerate the soil by adding oxygen and is both anti-fungal and anti-bacterial. Cannabis plants can be fed a mixture of hydrogen peroxide and water as a fertilizer and disease deterrent, resulting in healthy plants. It can be misted on the leaves and/or applied directly to the soil.
Do not use hydrogen peroxide if there is no reason to use it. Hydrogen peroxide can be really dangerous – if not used safely and responsibly. Hydrogen peroxide is available in different concentrations (or volumes), and can range from ‘mild to potent’. The volume of hydrogen peroxide that we work with is usually 35% food grade peroxide. This is an incredibly high volume, and can severely burn your skin, eyes and anything else it comes into contact with (especially when undiluted). Many growers opt to use a much lower volume of hydrogen peroxide (as low as 3%). At the end of the day the volume you choose will affect the dilution ratio.
Good luck with your project, I wish you all the best! 👽