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This was a reply to a thread that I posted, where people were discussing h202, pythoff, and food grade h202 etc.

I did a fair bit of research on this and this is what I came up with.



K firstly I have used H202 for around 2 years now and only recently switched to Pythoff. Im not saying NOT to use H202 but rather that there are better things that dont hurt the plant.

Heres a little bit of why-


First, the food grade H202 shouldnt be used as it is not designed to be used in a horticultral area.

Reason being is that food grade contain a stabiliser and also preservatives.

which are no good for a plant.

People are kinda right in thinking that when added to water it creates oxygen but actually creates ozone. lets remember our chemistry class for a minute-


When Hydrogen Peroxide is added to water it creates a certain level of Ozone,

Ozone will, having the opportunity, react with any organic compounds that are

present and this is called oxidation. Hydrogen Peroxide is water with an extra

oxygen molecule causing it to be unstable and when you add it to water H202 +

H20 = H403, the 03 in the equation is ozone and requires oxidation to break it

down into 02 which is stable.


The directions for use in hydroponics is 1 ml per gallon of water without nutrient

present in the water, if you add Hydrogen Peroxide to your nutrient solution then

you run the risk of the ozone reacting with the mineral salts allowing them to fall

out of solution. Do not use more than this because it may break down the outer

layer of the root hair making it susceptible to root disease which is in many cases

the very reason you are using it.


Hydrogen peroxide is sometimes used in hydroponics for increasing a nutrient’s oxygen concentration. It is not useful as a sterilising agent in hydroponics because it is only effective as an oxidant when the nutrient’s pH is around 1, which is far too low for plant growth. However, at pH values around 6, peroxide is both a weak oxidant and weak reductant. Consequently, when the pH value of the nutrient is 6, peroxide is destroyed by monochloramine - simply because monochloramine is a much stronger oxidant at that pH. Unfortunately however, because peroxide is normally dosed at 100 times the concentration of Pythoff, all the Pythoff will be consumed in this chemical reaction while only a small percentage of the peroxide will be destroyed.


Also another old wives tale is not to use tap water because it contain chlorine, or to let it sit to release the chlorine.

Well folks we NEED chlorine it is a required micronutrient.


Lets just say a few facts tho-

Chlorine is a REQUIRED micronutrient,

What it does-


1. Maintains positive balance in plant cell juice


2. Maintains displace pressure


3. Helps in the synthesis of Protein


TOO much can cause a problem also but like I said its hard to get too much.

too much will give you-

1.Yellowing of leaves and fall from plants

2. Fading of plant



Aluminum, chlorine, cobalt, iodine, selenium, silicon, sodium and vanadium are not normally included in nutrient mixes. They are required in very minute amounts that are usually present as impurities in the TAP water supply or mixed along with other nutrients.

This is why its not good to use reverse osmosis and heavily filtered water as these micronutrients are removed.


Also I had a laugh the other day, this guy was boasting about how "he lets his water stand for 2 days to remove the chlorine and then he treats the water with Pythoff and never has had any problems like other growers have etc"

Whats Pythoff made from??


CHLORINE!! hahahaha


Pythoff is based on monochloramine - a proven and trusted drinking water disinfectant used world wide in reticulated scheme water supplies.


I used to use oxyplus but got sick of it burning my hands.



Well I hope this was some help to you all.




Oh also bleach is usually a really strong chlorine based product, and h202 is hydrogen with oxygen in an unbalanced mix.


You can use bleach for cleaning all the equipment etc before growing the plants.

You could use bleech instead of H202 or pythoff but it contains Chlorine based, Bleaching agent, Non ionic surfactants, Anionic surfacunts.

Sodium Hydroxide and Sodium Hypochlorite.


Which are not good to the plant. ideal for inbetween grows though.


I've read all this but I'm still unsure how to employ the 3% or 5% peroxide. The instructions on the 35% were clear. Can I just place 3% peroxide directly onto the soil or does it have to be diluted.


US Standard

1.28*G/C= Liquid Oz's per day



10*L/C= Ml per day


C= % concentration of H2O2

L= Number of liters in reservoir

G= Number of Gallons in reservoir


Example: How much 3% H202 should I add to 7 gallons of nutes?

1.28*7/3=2.986 Oz's each day.


How to use it.

H2O2 comes in several different strengths 3%, 5%, 8% and 35%, also sold as food grade Hydrogen Peroxide. The most economical is 35% which we recommend be diluted to three percent before using, as at this high concentration it can cause damage to skin and clothing. When working with food grade H2O2 it is very important that you clean up any spills or splashes immediately, it will damage almost anything very quickly. This is extra important with skin and clothing. Skin will be temporarily bleached pure white if not washed cleaned. Gloves are strongly recommended when working with any strong chemical.


Food grade H2O2 can be diluted to three percent by mixing it one part to eleven parts water (preferably distilled). The storage container should be opaque to prevent light from getting in and it must be able to hold some pressure. If three-liter pop bottles are available in your area they are ideal for mixing and storing H2O2. There are twelve quarter liters (250ml) in three liters, if you put in one quarter liter H2O2 and eleven quarter liters (250ml) water in the bottle it will full of three percent H2O2 and the bottle can hold the pressure that the H2O2 will generate. Three percent Hydrogen Peroxide may be added at up to three ml's per liter (2 1\2 tsp. Per gallon), but it is recommended that you start at a lower concentration and increase to full strength over a few weeks. Use every watering even on fresh cuttings. For hydroponics use every reservoir change and replace twenty-five percent (one quarter) every day. Example: In a 100L reservoir you would add three hundred ml's (3%) H2O2when changing the nutrient. You would then add seventy-five ml's more every day.



information was taken from all sorts of places including- http://www.marijuana.com/Bible.php?loc=43&id=23



IMO it should not be used in soil as it will kill everything in the soil. So ask yourself WHY are you growing in soil?? if its for the organics of it then h202 will kill them all.

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Havnt used anything else but i ve been using Pythoff for a while now and i reckon its good stuff , just cant use it with organic ferts .


Didnt happen to get the Pythoff test kit did ya ferengi? Have been thinking about gettin one but ive never had a problem with water so i havnt bothered but still it would be nice to know your dosing properly.

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hey guys found some hydrogen peroxide in bathroom cupboard today and was curios if it would have a problem with AU60???


take care and peace out


:thumbsup: :thumbsup:

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I think it will be ok with AU60 as i am using a new product which is a copy of AU60 and the mfg said i can use h202 with it.


the 50% oxyplus is added at 2ml per 10lt. so if yours is 3% you would add it at 3.33 ml per litre. 4ml per litre is fine. ive added oxyplus at 4ml per 10 litre and had no problems. i add it every 2 days. cheers


i havent tried pythoff but will try it once i finish the oxy to see which is better

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im pretty sure the 3% is the one used to sterilise cuts etc by faulding and is ok. but its a weak strength and not cost effective


before oxyplus was released, i used to buy the 35% peroxide by the litre from the hairdressing wholesaler. its not food grade but neither is oxyplus. just dose it proportionately.


but ive done the maths and oxyplus at $90 for 5lts is the best value for h202 i could find anywhere.

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Is there any data showing h202 to be harmful to plants? Because I'm using it at the moment, and I'm putting 6ml daily into a 60ltr tank. The plants leaves seem to have risen and it looks really happy. But i'm four weeks into flowering and the buds are looking small. I'm curious if oxy affects the roots ability to absorb nutes? Just a long shot. I started using it when my plants were growing slowly and they doubled in speed so dont' think it's oxyplus. Can't help but wonder tho
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I also let my water stand for a few days . The reason is this the dissipation of chlorine causes massive ph fluctuations and ph scale is logrythmic so if your ph rose from 6.3 to 6.7 it would be 3 to 4 for times more alkaline .Phythoff (which is as stated monchloramine )does not cause ph fluctuations.


It is highly unlikely that one would get pythium from treated tap water but there has been a large increase of cases due to the drought .


A lot of growers use tank water in the mistaken belief it is better for ones plants this is a fallacy and is a good way to actualy get the dreaded pythium. The only way to have pure water is to use a reverse osmosis filter.

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