Keep getting powdery mildew, can i use Hydrogen peroxide in coco?

I keep having to restart my plants, they keep getting powdery mildew. I feel it has something with the mycelium product i used over a month ago. What would happen if i water in the coco with with hydrogen peroxide to try and kill whatever bacteria is living in the coco? I have flushed many times! I feel like unless i dump the coco its just going to keep happening. Please HELP!


Bacteria and mold are 2 different things. Peroxide will kill both mold and bacteria, but I’m not sure that it takes out mold spores.

Mycos will not create mold problems. Humidity and lack of airflow are the main causes. It would be a mistake to try to kill off the mykos in your coco.

I’ve never heard of someone treating soil (or coco in this case) for a mold problem. Peroxide will kill WPM on contact on plant surfaces. It will also kill the beneficial microbes (bacteria) in your coco. I wouldn’t put it in your coco. It does not help mold at all and doing so creates other problems.

The best you can do is use peroxide on the plant surfaces where WPM appears. WPM isn’t that hard to kill off that way.


Do you have pics of the issue?

Ok, thanks very much for taking the time to explain that to me. Im extremely frustrated. Peroxide will kill spores, btw.

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I had PM this season. I am outdoors, with soil.I used this on my plants, and cut down the irrigation frequency also.

SL out.

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A clarification:

Mykos is a form of micellum rather than a mold. Peroxide does not kill micellum. I use it to treat mold on my micellum grows when I grow mushrooms.


What about keeping the humidity as low as possible? as in not using a humidifier for correct vpd?

Good idea.

Chasing VPD is more frustrating than it is effective. I keep it simple and shoot for >50% in veg and <50% in flower.

If you are having problems I would reduce RH to ~40% if you can get it there (assuming the plant is at the stage where 40% is tolerable (e.g. well into veg.)