Hydrogen Peroxide (H2O2) and Hydroponics

Author: Kevin Espiritu

Hydrogen Peroxide (H2O2) and Hydroponics


Hydrogen peroxide is an invaluable tool in your hydroponic garden…if you know how to use it.

Before we look into how to use hydrogen peroxide in hydroponics, let’s look at the compound itself.

In essence, hydrogen peroxide is just water with an extra oxygen molecule attached. It’s found somewhat abundantly in nature, up in the atmosphere and in rain or snow. As an unstable compound, it sheds its extra oxygen molecule readily and becomes water and a single oxygen molecule. This makes it a very effective compound in hydroponics for a variety of reasons:

  1. Effective sterilizer of your growing medium and growing environment as it breaks down into water and oxygen after use.
  2. Can increase germination rates
  3. Encourages more vigorous vegetative growth
  4. Adds oxygen to your reservoir, killing off harmful bacteria
  5. Increases nutrient uptake by your plants’ roots
  6. Eliminates chlorine in water quicker (great if you are using tap water in your garden)
  7. Promotes root health

How to Use Hydrogen Peroxide Effectively

Once you’ve purchased the right concentration of H2O2, you need to figure out how much to use…and when. A great place to start is to test out 3ml/gallon of water in your reservoir to start out with. So for a typical 10 gallon reservoir, start out with 30ml. Then add in 15ml, or half of the starting amount, every day. Monitor the health of your plants roots and vegetation from there and see if you notice any changes.

When you add it to your reservoir, a few things are going to happen. As I mentioned before, it’s an unstable compound, so the extra oxygen molecule will break off quickly. But what happens to it once it’s free?

It’s looking for a fight.

If it runs into another oxygen atom, it’ll attach and form O2. Which will be used by your plants’ roots, causing your plants’ stems to be thicker, their foliage to be more vigorous and deep green, and overall increasing your plants’ health across the board.

If that O2 molecule runs into another organic molecule – like a virus or spore – it oxidizes, destroying the virus or spore.

So you really can’t go wrong using peroxide in your hydroponic garden.

Potential Dangers of Using Hydrogen Peroxide

If you decide to go with the food-grade concentration, be aware that it is corrosive. Do not handle it without gloves and do not get it on your skin. Put it in an area that’s away from the reach of children or animals.

Other Uses for Food Grade Hydrogen Peroxide

Aside from your hydroponic garden, there are all sorts of clever uses for food grade hydrogen peroxide.

Here are a few:

To Soak Veggies

You can extend the life of your greens by soaking them in a solution of hydrogen peroxide and cold water. Soak them in a 3% solution of h2o2 and water for 20-30 minutes, or lightly spray them. Be sure to rinse, drain, and dry them before putting in the refrigerator – wet produce has a terrible shelf life.

As a Kitchen Freshener

Dilute food grade H2O2 with 10 parts of water for every 1 part of H2O2 and put into a spray bottle. Use it on your counter and kitchen gadgets as a disinfectant. Also works well to remove bad odors.

As a Dishwashing Agent

No matter what you use to wash your dishes, you can add a few fluid ounces of 3% H2O2 to it to improve its’ cleaning powers.

When Growing Sprouts

Add 1 fluid ounce of 3% H2O2 to the water you use to soak your seeds. When you rinse them, repeat the process.