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Post- Production Sterilizing Using Hydrogen Peroxide (h2o2) Vs Common Household Bleach

Discussion in 'Hydroponics' started by AnselAdams, Feb 11, 2019.

  1. I Hope this helps someone as much as it helped me. I tried several different places and types of resources to get information on this question. This is a discussion that I found that seemed to put it all of the bits and pieces in one place. I hope it will be as useful to others .

    I would like to hear what others are doing and why. Just as a point of discussion. There lots of ways to accomplish the same goal.

    Peace Out!

    Two Methods to a Great Clean: Sanitizing and Sterilizing

    "... The most common chemical cleaners used as sterilizing agents in horticulture are bleach and hydrogen peroxide. When you are sterilizing with a chemical cleaner it is always a good idea to wear gloves and goggles to protect yourself from potentially abrasive chemicals.

    Common household bleach usually contains the active ingredient sodium hypochlorite, which is the same chemical compound commonly used in disinfecting waste water at treatment plants. Bleach is a great sterilizer but can leave a residual so equipment needs to be double or triple rinsed.

    After every harvest, a hydroponic crop grower can create a bleach bath (1:1 water to bleach) to soak the hydroton, air stones, submersible pumps and net pots to ensure they are all sterilized before starting the next crop. After soaking in bleach solution, growers should triple rinse all equipment before using it again to ensure all potentially harmful residues have been removed.

    Hydrogen peroxide (H2O2) is water with an additional unstable oxygen molecule or an oxidizer. Its composition is truly valuable to the horticulturist because as hydrogen peroxide breaks down and loses its unstable oxygen molecule, it turns into water: H2O. Water is obviously non-toxic to plants and beneficial microorganisms so it is an ideal byproduct of sterilization.

    I prefer hydrogen peroxide to bleach for the sterilization of nutrient reservoirs, hydroponic systems and all propagation equipment including clone machines. Reservoirs, cloning equipment, and hydroponic systems can be wiped down with a clean rag saturated in 3 per cent hydrogen peroxide.

    For larger hydroponic systems or systems that are too difficult to wipe down, a diluted 35 per cent hydrogen peroxide (2:1 water to 35 per cent hydrogen peroxide) solution can be run through the system for one hour. Rinse the system with clean water to rinse out any remaining hydrogen peroxide before returning the plants.

    For sterilizing clone machines, run a 4:1 water to 35 per cent hydrogen peroxide solution for about an hour. As with the hydroponic system, rinse with clean water before returning clones to the machine. Extreme caution must be used with hydrogen peroxide especially when it is in higher concentrations. Growers should always protect skin and eyes from contact with concentrated peroxide.""
    Last edited: Feb 11, 2019
    gwheels and Dan789 like this.
  2. Nugg


    All I can say is..don't run sterile system...keep the beenies...I tried sterile system..never oldest system is 3yrs running.never cleaned.never issues.its just so much easier for me..
    JWM2 likes this.
  3. I do a 100% change between grow and flower when i switch cabinets Based on my days of running a 300 gal reef tank for 8 years, I do a 100% water change, then add back about a gallon or two (depending on size of res) of the old water to return the bennies to the system.

    Resetting the system, assures me that each grow starts with the same conditions. Makes spotting problems easier for me.
    Homesteader and JWM2 like this.
  4. Nugg


    Yeah.. don't get me wrong..that system I mentioned holds 80gal.i drain down,leav lea few gal.of the old,clean air manifold,then refill...can't leave the beenies if you add peroxide...I guess I miss understood somewheres...but this I can't have beenies and run any type of peroxide or sterile's one or the other.
  5. no foul, no harm :)

    I wasn't exactly crystal clear there....
    The res on my flower cabinet is 35 gal. so i do understand the work effort. It is a lot of work to pull all of the crap out of the cabinet, wipe it down, etc. Done right it takes me two hours to clean the flower cabinet. By running the H2O2 mix through the entire system, would get to the parts that cannot be reached (more likely forgotten) like inside the hoses.

    Lol; If if had to deal with an 80gal res, i would probably re-think my process as well.
    JWM2 likes this.
  6. In my whole life I have never sterilised any pot or rez. Only used warm soapy water to clean things out.
    JWM2 likes this.
  7. Physan20 is a hundred times better then bleach or h202. Turns into nitrogen in 2-3 days. So between harvest I run at 1 tablespoon per gallon trough my system and let it sit there for 2-3 days, quick rinse and your good to go. Cleanliness is next to godliness lol.
    Some of you guys must have never ran into a real plant disease issue because running h202 does not do anything to kill real pathogens.
    I’ve dipped clones dying of disease in h202 and it would stop the disease for about an hour then they droop right back down.
    Weather your going sterile or bennies the watering system needs cleaned between harvest. Especially if there is any down time where water in the system will sit.
    If not eventually you will run into problem weaTher it’s from taking in sick infected clones or just bad husbandry issues.
    cemchris and AnselAdams like this.
  8. ... Cleanliness is next to godliness lol. AMEN!

    Thank You Trustfall.
    Got it! Physan20 found it on Amazon. I will be doing some more research and reading on the product. However; reading the Amazon page, it looks very promising. As an engineer my brain tells me i have to always start with a know base and work up; so that is the way i garden.

    Anyone else use Physan20?
    Trustfall and JWM2 like this.
  9. Your welcome. It’s a fantastic product and disease/bacteria do not build resistance to it. I use it at 15 ml when cleaning the watering system as stated above. If you have a diseased sick plant you only. Use 3ml per 5 gallons of water.
    If your grow is small and your not growing old passed around clones then you may not run into disease problems. But when your growing clones 10,20,30 years old they have much weaker immune systems then a fresh seed.
    I lost a ton of old genetics trying to fight disease before I knew much about it. I would cut 100’s of clones taking all precautions to be clean, following lots of advice but nothing would work. They would fall like dominos in days of cutting them. I haven’t lost another strain since I found physan20.
    I can spot disease from a mile away, as soon as they look at me funny I’ll do a 2-3 day treatment then i get them back onto hydroguard.
    Crown rot, pythium, fusarium you name it physan20 will take care of it.
    The only thing it won’t take care of is if the disease makes it into the stem of the plant. It’s not systemic so it doesn’t go up the plant to kill. In cases like this you have to use phyton35 which will go up into the plant.
    AnselAdams likes this.
  10. Physan20 arrived today. I will be bringing the grow box online in the next day or two. When i do; i will run the entire system intact for a week (i know you said only 3 or 4 days, but since i have to go out of town again.... a week works. I will flush and rinse on Saturday after I get back.

    Thank You.
  11. Your going to run the system with no plants for a week? That is no problem. You can go anywhere from 10-15 ml per gallon like that but it is going to be strong smelling.
    Remember only 3ml per 5 gallons if your watering plants.
    AnselAdams likes this.
  12. gwheels


    This helps me a lot with my system. I will get a gallon of 35% H2O2 if i can find it. Where does one usually get that at a pool supply?
  13. Amazon or the grow store.
    cemchris and gwheels like this.
  14. I don't smell will be an issue. I will mount the other filter as soon as amazon delivers the connector tonight.

  15. Trustfall... Question for you.

    Should i leave my chiller at 65 degrees? I don't think this stuff is a live culture but the nitrogen transformation process you described sounds like it may stop if temp is too low. I expect the reaction to be slower at the lower temps; but the smell you mentioned should also be less. ;-).
  16. I always use bleach to clean a room after a run. Tables, hoods, walls, ceiling, floor, drip manifolds. The thing with bleach is you need to run above a 10% bleach solution to make sure you kill everything. I just simple rinse and done on the table and drip manifolds. Don't rinse anything else. I have used h202 in the past it's just bleach is cheaper. That's the thing about bleach. Strong smell. If I was running sealed rooms I wouldn't be using bleach for sure.
  17. Just going to be a cleaner type smell. Are you exiting the air outside? What kind of system are you cleaning out?
    I would turn the chiller off if there is no plants in the system.
  18. I have dumped all that crap out and ran a light scrub brush over everything with the cleaning solution. There is 8 gallons of water in the system no plants, no nutes. just letting it run. If i can save the money for the week i will tell the spouse to turn it off (I am now running two of them, one for each cabinet).

    I have wiped everything in the cabinet down including the fan blades & cage.


    P.s. I poured about a quart into the humidifier as well.

    Photo taken at end of last run.

  19. P
    ok I see it’s like a homemade areoponics system. You will be fine. I always use gloves too. For some stupid reason in the instructs their is a dosage for your hands and it’s pretty strong so I don’t chance it. That stuff is going to start your next crop on a sterile environment.