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How much Hydrogen Peroxide?

Discussion in 'Hydroponic Growing' started by sunndropper, Aug 11, 2010.

  1. Hello. I am going the Hydrogen Peroxide route to keep my roots healthy. This is because I recently had a small problem with root rot. I have a DWC system and am wondering how much Hydrogen Peroxide I should use, per gallon of water. I also need to know what strength of Hydrogen Peroxide I should be using too. Any recommendations? Or should I be posting this in the beginner's section?
  2. Im trying to track down the exact formula for this but just for curiousity sake do you know what strength peroxide you will be using? Drugstore brand being 3% or concentrated grow peroxide at 35% etc.
  3. I'm not sure what strength I should be using. If the 35% kind is available I guess I would be using it because I wouldn't have to keep buying bottle after bottle of the 3% kind.
  4. http://forum.grasscity.com/hydroponic-growing/639303-peroxide-hydro.html

    There was a discussion there. With drugstore 3% a TSP or a capfull a day is probably good/beneficial/no harm. The big thing is introducing it with water so it doesn't hit the roots directly, and not adding to much at one time. IF you have problems a 1/4- 1/2 cup of 3% followed by a flush after 15 minutes, then pure water, 1/4 cup, flush after 10 minutes, then a day of pure water will do you good before flushing again and readding nutes.

    With the 35% a TSP I believe is the dose total. No more. Like I said, from what I read the thing is slowly adding it to the system. So with the 35% I have no clue how to do this. But I would think with 3% you could always start with a TBSP first day, then do capfull every day with no harm and beneficial results. Monitor the PH and PPM to see what happens.

    I just add it every once in awhile, a tsp or so. I recently did a whole flush right before flowering. I have high temps, and at one time a non light proof container. Just monitor how much you add, what you see in the tank/plants, adjust, monitor some more, and figure out what works for you is the best I can gather. I would stay away from 35% unless I was doing a big grow with a big resevoir feeding plants. If its a small dwc, 3% I'd probably aim for a TSP a gallon, maybe a little less or more, over a period of 7 days or so between flushes.

    This is just from my small grow, what I've read, and guessing. The things I know for sure is don't let h202 hit the roots directly, and its best to add it over time instead of all at once unless your about to flush it all.

    *edit* I probably use/recomended too little, but I'm trying to keep it safe and haven't seen any algae so I'm using what works for me. What I recomended, like I said, is actually higher than I use. I use a capfull every other day. I change water weekly.
  5. Hey, thanks for the info.
  6. from a couple different sources I've seen some different stuff. one site said 17ml/L of 3% h2o2 or 1.7ml/L of 35%. Another site said for regular use 1/2 cup per gallon of 3% or 1 cup per gallon for infected plants.
  7. i add about a capful of 3% store grade h202 per gallon in my res, which is a 10 gallon res filled with about 4-5 gallons. i suffered from root rot when i first started, with my res temps averaging about 78 degrees F. after adding the h202, root rot has not come back, despite my res temps being in the upper 70s. so for all those people who say res temperature is the only way to prevent root rot, theyre wrong.

    people also love to say that lower temps can hold higher amounts of dissolved oxygen, but studies have shown that a 10 degree difference in water temps (about 65-75) only holds about 1% more DO in cooler water than warm water. so cold water temps dont really do that much. what would be most beneficial is either a stronger air pump, or adding h202.

  8. I find a capful of 3% once a week keeps the roots active white and happy...
    you dont want to use to much as it will stunt growth.. the benificial bacteria will also be effected... so this is a case where less is more....
    even every other week would be fine....
    higher temps with the proper circulation wont cause root rot, however in a res that does have flow... those temps will create root rot in a hurry.....
    so when dealing with temps just make sure you have plenty of water movement and bubbles and all will be well...imo:D

  9. Should the amount of hydrogen peroxide be adjusted to a lower dose for seedlings? Ive got 9 seedlings going on three weeks old from seed in a 15 gallon dwc and im seeing some drooping on about half of them while the others seem fine. Ive got them in pure distilled water and my water temps are between 70 to 72 with the temps in my closet running between low 70s to mid 80s during the day. Im wondering if hydrogen peroxide might solve this problem.
  10. #12 sunndropper, Apr 25, 2012
    Last edited by a moderator: Apr 25, 2012
    Thanks everyone! I really appreciate the help. I have two ebb & flow systems that I keep running. I don't use Hydrogen Peroxide anymore because I am using Roots Excelurator. I just am doing flood trays with small garden herbs for now. I have been having great results using the Roots Excelurator with the General Hydroponics line. When I harvest, I have been seeing totally healthy, massive and dense root masses. I don't use an airstone but just keep the nutrient solution mixed up by using a water pump. The House & Garden website says that the Roots Excelurator works the best without air bubbles in the reservoir. The bad news is that I was having this issue of a shiny film developing on the surface of the nutrient solution. So if I didn't stir the film back into the nutrient solution every time right before flooding the tray, the pH would drop overnight and be way out of range the next morning. I used to buy purified water but am now filtering the tap water from my house. I have a HydroLogic Small Boy, with the special upgrade carbon filter installed in it, to remove the chloramines. I just recently used it for the first time and the shiny film is not developing. I am keeping a close eye out for the shiny film though so I can know if it no longer is happening.
  11. i am currently doing a dwc grow and i noticed today that my roots had a slight bit of brown color to them so i went and got some 3% h2o2 and added about 2 tsps to my 1 gal bucket, and i hope that takes care of the developing problem. my water temps were way up to about 80 F so i dropped it by raising my lights up to the vent, and added some ice cubes. at last check about an hour later the temps were at about 55f, and the cab temps were at 73f. i hope this bit of dedication pays off, reverses the problem. now my question is this, how can i control my water temps without the aid of an expensive water chiller, or keeping my lights so far away from my tops?
  12. if you give them too much hydrogen they will droop as well, but mine have bounced back, the reason for your drooping needs to be fixed within the system instead of adding another chemical to the already complicated mixture....

    Make sure your water is cool, and the air is fresh, and you're in the bud
  13. I tried 5ml first time, 8ml the second and it took 15ml/gal before I started to notice a difference, plants absolutely love it, this is the 3% store brand. For me a capful wouldnt be enuff, my water temps sit at 68 to 72ish, it does have a swing but no more rot since doubling my dose of h202
  14. just wash those things up with RO water and make some EWC tea to prevent that root rot! :)

  15. good info. here! keep the light out and temps. down, BELOW 70, lol. dilute h2o2 before adding to rez. h2o2 is def. a bennie killer! i believe there are other (chemical) alternatives to h2o2.
  16. You can't use h2o2 in an organically grown hydro system either, this kills the beneficial bacteria.......

    Like I said before, if you have to use h2o2 just to run your hydro system to keep your plants from defeciencies and/or killing it you need to look into your system and make some changes.
  17. Read the article posted at the very bottom of my signature. It's precisely about this subject. I think you'll find a simple answer.

    The only time you'll need peroxide in your system is if you're running really rich co2, and electrolysis of the nutes is unavailable. I'm going to assume that neither of these apply.
  18. Just read Original's post on how to avoid root rot... I read it a few times before my first grow and it makes a sense.

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