How much h2o2 is too much?

Hello everyone, i have one plan in soil and another in hydro (bubble ponics)

i was thinking of having soil and aero from now on,and one in bubbleponics so i don t waste any materials

my friend let one of our babies die due to over watering in soil, and nute burn
so my question is : how much h202 can i feed the plants? in soil and in hydro/aero?

if it has a limit, why is the limit? causing root burn? or too much acid or something?

cuz root rot in soil due to over watering is lack of 02 amoung other things, so i was to flush the plant with water+h202 ph ballanced.

and is it different? the amount i can put of h202 in soil compared to hydro/aero? how much ?

thank you all
ps: i m still a noob

only use h202 in soil if you have to flush due to something like root rot, because when it hits the micro organismism in the root system that help with nutrient uptake it will kill them

too much h202 WILL kill your plants...start with one or two tablespoons per gallon

but alot of hydro growers will use a tbsp of h2o2 throughout the grow

I use 1000 ppm H2O2 in soil with hydroponic fertilizers and water the plants every day with this solution. This is a way to get hydro yields in soil. Think of it as a once per day ebb and flow. By using hydroponic fertilizers I'm not relying on any bacterial action.

A preemptive NO, 1000 ppm is not going to fry the roots in soil.

I avoid H2O2 with actual hydroponics unless I'm having problems.

It's best not to use H2O2 with organic fertilizers.

techhead420 said:

I use 1000 ppm H2O2 in soil with hydroponic fertilizers and water the plants every day with this solution. This is a way to get hydro yields in soil. Think of it as a once per day ebb and flow. By using hydroponic fertilizers I'm not relying on any bacterial action.

A preemptive NO, 1000 ppm is not going to fry the roots in soil.

I avoid H2O2 with actual hydroponics unless I'm having problems.

It's best not to use H2O2 with organic fertilizers.

Click to expand...

what nutes are you using? and how do you keep the ph and salt buildup down

sir smokesalot said:

what nutes are you using? and how do you keep the ph and salt buildup down

Click to expand...

I use General Hydroponics 3 part and run at 1/2 strength as recommended on the label- per gallon roughly 3 mL grow, 3mL micro, 8 mL bloom. I had a pure sativa that could take full strength but my indica will show nute burn at full strength.

pH 6.5 which is a little higher than most to deal with pH drop/acid build up.

Once per week or two (depending on the plant) I flush with water. The water is also 1000 ppm H2O2.

Under a 250 watt HPS with nine plants in a 4 square feet grow area I get 3.5 - 4 oz per month (without CO2). The plants are in 5 inch square pots with seedling soil.

When temps are cooler I run CO2 off a tank at about 1500 ppm and cycle a fan as needed for the humidity (without CO2 the exhaust fan is always on).

Even with house plants I use 1000 ppm H2O2.

Don't use H2O2 with organic fertilizers. Organics rely on bacterial action and these bacteria are going to be oxidized.

I always add H2O2 at the time I'm adding the solution to the plants. You should not leave H2O2 in a hydro solution for extended periods at the levels I'm running it. Over a period of three days or so the hydro fertilizers solution starts to become oxidized; you can see the effect as the solution turns from a light pink to clear.

Root rot, harmful bacteria and over watering is a thing of the past if you use H2O2.

The best way to go is to get some 35% H2O2. I dilute some down to 3% as a working solution for safetyand add this 3% solution to the hydro solution as needed.

Hope this helps!

looks like u know ur business, if your numbers are acurate, nice crop....
so mainly wut you all said is... too much h202 will fry the roots..

yes i know about the h202 breaking down organic molecules and micro organisms...

you say to hydro, 3% of 02 in the water is the way to go, like 97% of ro water+ 3% of (hypotecticaly) pure h202 100%..

in soil i didnt get a percentage.... and second, u say you use a 1000ppm h202, and hydro ferts..... do u put just h202, until reaching 1000ppm and then add the nutes? or, all toghether is 1000ppm

in theory, as another user said and proved in this forum.... you can get away with almost 3000ppm nutes... as long as the plant has enough water, oxygen and c02 to mach for the ''production formula'' to process all

and don t build up excess of nutes, causing the burn

kit of like ''turbo charging'' a car.... throw more, as long as in the right amounts and the spark does its job

that was one of the reasons i asked, how much is too much, because, if it didnt harm the roots, you could get away with feeding 100% h202 + a lot of nutes, and the growth rate would increase exponentially... if you know what i mean

+ not having to deal with nute burn or any type of root rot...


i dont know how to figure the % of h202 of the package, you guys said 30% i have read 50% (users that use different type of h202).... my bottle says
"500ml" - "10vol.''

and thank you all
best regards

I've heard of people going 3000 ppm with H2O2 and have gone up to 2000 ppm myself. I didn't notice any obvious implovement in performance at 2000 vs 1000 so I dropped down to 1000 ppm.

I didn't actually say 3% in water, what I meant is that I take some of the 35% peroxide, and dilute it down to 3% (in a one gallon jug in this point) and when I need some H2O2 I use this diluted H2O2 to add to the hydro solution and get it down to 1000 ppm (0.1%). This is only for safetey, I've splashed 35% peroxide on my hands before and it will burn. I tend to rip a bong hit before messing with the plants and prefer not to work with dangerous concentrations when I'm high.

I don't know how high of H2O2 levels that you can go but as I said above, I didn't notice differences between 2000 and 1000 ppm and I prefer to error on the side of caution when adding an oxidizer to the roots. I have read of a person using 10,000 ppm (1% solution) as a one time dose to kill pathogens in the soil but I would caution people from using such high levels without trying it on one plant to see what happens.

I mix up a batch of hydro solution once per week. I use a small jug to to actually "water" the plants. I add the H2O2 to the smaller jug after it's filled so that the main batch does not have H2O2 in it. H2O2 breaks down in three days or so when exposed to other chemicals so you add it at the time it's needed.

The only reason I don't have nute burn is because I'm running lower fertilizer levels, it has nothing to do with the H2O2 levels (but it's nice to have it dialed in!).

Don't feed 100% H2O2 to your plants (not that you could fine any). To much of a good thing can quickly turn into a bad thing. Start off with low levels with a plant and see how high you can take it. Don't experiment on your whole crop!

ok... thank you for the input on ppm vs performance
you get the h202 and to your own, less agressive soluntion, and store it, and when ever u need it, u ll use the less agressive,

thanks for all the help

really old thread, I know, but very useful and help my over watered plant to bounce back, impressive what a bit of H2O2 can do over night to a droopy plant in soil

lots of info out there on H2O2 but very few places that clearly explain both the effect and how to use it in detail, and it don't help much that some talk about 3% wile some talk about 17% or 35% or higher (tho seems you have to delude it to 3% before use no matter what)

also, some only refer to the use in hydro some both hydro and in soil and then agin some as misting (but that is for Pm/mold I believe)

and some talk about daily/weekly use/treatment wile some only talk about the use for root rot or other deceases, the amount also vary a lot from threat/post/article

another thing I quickly notice, when I used a few hours of research on the topic, is that it really split up the growers in "two camp`s" so to speak, some think its natural as its found in Rain and wont even hurt a organic soil grow others wont even touch it and claim its only for hydro and will "destroy" a organic soil

so pretty hard to know what to think, and find answers on how to use it and how much to use aso.

one thread told me to use half a cup 3% in a gallon of water another told me to use 30 ml, some places I found info that told me to let it sit over night before use, some said two hours, yet agin some told me to add it right away as H2O2 quickly "evaporate" some agin told me to add a high concentrate of nuts with it , some did`t, some places they talked about adding a root booster or similar but did`t say if it should be added to the H2O2 or given after/before the "flush" agin some said to flush the pot with it, if over watered, some did`t mention anything or just said to water untill you could see a bit of run off ? some said to pour the water in fast to flush old staggered water out aso.



well long story short, I used 3 table spoons (about 30 ml) of 3% H2O2 in a gallon of temperated tap water (tho not to hot, 18-20C is suppose to be best with H2O2 as the oxygen level in water drop as the temps raises)

I used a root booster and a bit of GH micro/bloom (normal dose) before I added the H2O2 to the water Can and used it right away (tho I have a air pump and made a DIY tube with a "million" holes in it and used it for 5 minutes to oxidize my water a bit before giving it to my plant, I watered quickly untill I could see a bit of run off (in the end maybe 10% in the tray) and empty the tray after 10 minutes so it did`t stand in the water to long

I moved the fan a bit closer and turned up the temps from about 74F to 79F



I over watered the plant on sunday, well so it seems, monday it was beginning to get droopy, and it was a very healthy plant to start with (sorry no pics taken, had "my hands full")

I gave it a day to see if it would get better, but tuesday it looked bad with most top grow hanging down, so I did some research and got the H2O2 on wednesday and gave it to my plant, who now seemed even worse with almost all leave`s hanging down

to day thursday I got in the grow room to see and found my plant almost looking as it did before, I would say a 90% recovery and its still only 20 hrs since I gave it the H2O2 so lets see ...


hope this help others in the same bad situation

First off, the idea of using H2O2 with soil is mistaken as it will immediately be neutralized by soil contaminants. It is intended to be used in a hydroponic reservoir to control water molds and similar parasites. For dosage, have a look at the instructions posted by Al B. Fuct - he is probably the single most experienced user of H2O2 on this site.

Notably, I had a problem with what I believe was pythium and used H2O2 to control it...at first. Then I switched to GH Floranova (no H2O2 as it contains organics) and the pythium problem vanished. I can't say for sure that the Floranova eliminated the pythium problem, but the circumstantial evidence suggests that it did.

well I dunno, I just know that I had one of my most healthy looking plants ever getting over watered and droopy, looking really bad, but after adding a bit of H2O2 water it bounce back a day after, to day (40 hrs since I gave it to em) they are totally back to "normal" if not even better looking, all top grow is pointing upwards a bit with a slight bend upwards to the leaves

a cheap fast fix, instead of weeks of battling it with a good chance of a dead plant in the end

old thread but pretty good thread so want to summarize what i learned about h202.

the recommended dosage on my 35% bottle is 3mL per gallon that is .0277% (277ppm) pure H202. I read on another thread that you can use 5ml and be safe so up to now ive been using 5ml per gallon.

Now i now buy the 3% its sold at walmart and its just as cheap if you calculated it out as the 35% sold at the biggest hydro shop in state. Walmarts closer and dosent burn my skin if i spill it.

Since reading this thread I will be upping my PPMs from about 500PPM to 1000PPM. I am doing coco/perlite mix outdoors and without h202 green shit grows on the sides of my pots i dont know if there is root rot but if anyone knows how bad green scum is let me know. The pots get too hot and too much light if i was indoors i wouldn't need as much h202 cause temps would be down.

Im going to let the plants bath in an inch of water that will be dried by night everyday which i havent started yet. do you think i need more or less h202 with that. im thinking more maybe i should go to 1500ppm hmmmm.


also dont use h202 with organics. you can use it with synthetics. it replaces the hygrozyme and aquashield dont use them together but you can alternate

Still good information, not a lot out there.