how much 12% hydrogen peroxide do i use for 10 liters of water please help

i am in aeroponics and want to add a dose of hydrogen peroxide, only i dont know how much is safe add to 10 litre of water, please help

You don't want to add more than about 0.75ml/L of a 12% solution. And you'll want to start it at a lower concentration initially. So, I would add about 2mL to your 10L of water to start. If you do water changes, that's when you increase the amount you add. That is, change all 10L, add 3-5mL. Change all 10L, add 7mL.