SaraJean asked a question about peroxide...

[PaphMadMan]

I'm not sure where you are seeing a recommendation for hydrogen peroxide soak, but I would consider it a very bad idea. Not only is it largely useless, but can cause extensive damage. It might seem like a valid idea for cleaning a cut or broken point in a root, but it can be translocated through the vascular tissue of the plant and cause an extensive area of necrosis, almost guaranteeing rot in the damaged tissue.

[WaterWitchin]

Originally Posted by PaphMadMan

I'm not sure where you are seeing a recommendation for hydrogen peroxide soak, but I would consider it a very bad idea. Not only is it largely useless, but can cause extensive damage. It might seem like a valid idea for cleaning a cut or broken point in a root, but it can be translocated through the vascular tissue of the plant and cause an extensive area of necrosis, almost guaranteeing rot in the damaged tissue.

Agreed, PaphMadMan. I see that recommendation on and off from time to time here. I am NOT in favor of it, and think it's a bad idea. Pretty sure SaraJean feels the same way, but can't speak for her. I was looking for the science behind it, as her question posed, when giving the response of Oh HECK NO...Don't do that! Otherwise, it's a hard argument to make against someone whose friend does it, or it must be true because I saw it on a YouTube video.

---------- Post added at 09:54 AM ---------- Previous post was at 09:48 AM ----------

Originally Posted by Ray

Having worked with drugstore-grade 3% H2O2, 50% industrial grade, and Biosafe Oxidate @ ~0.1-0.2% H2O2 application rate, I can provide some anecdotal comments backed by a small amount of science.

3% H2O2 is basically worthless as a disinfectant. The stabilizer in it is so weak that it completely decomposes within seconds of application, leaving behind a pool of water in which pathogens can multiply. Does it damage the few root hairs orchids have? Maybe, but I doubt it's significant due to the transient nature of the peroxide.

Some growers claim it is a good oxygenator of potting media. Yes, it releases oxygen as it decomposes, but that too is transient, and using a water breaker and watering heavily probably does as much benefit.

50% H2O2 is much too corrosive of anything metallic or organic.

Biosafe Systems Oxidate (a.k.a. Biosafe Disease Control) has a very weak concentration of peroxide, but it is stabilized with peroxyacetic acid, so it is a very good disinfectant, as it stays chemically active until it is dry. I used it extensively in my greenhouse in PA, as a general spray and as a repot cleanse, and I never saw any sign of phytotoxicity - no doubt due to the low concentration. It will corrode skin if you have contact with its concentrated (27% H2O2) form.

Interesting, and never heard of Biosafe Disease Control. Appears to be something I'd like to put in my "just in case" arsenal. Would that be something one could sterilize LECA with? I have several gallons of LECA that's barely been used, and seems a shame not to reuse. Of course, I throw away old yucky stuff.

What in the heck does one use industrial grade H202 for?

[Ray]

Originally Posted by WaterWitchin

Interesting, and never heard of Biosafe Disease Control. Appears to be something I'd like to put in my "just in case" arsenal. Would that be something one could sterilize LECA with? I have several gallons of LECA that's barely been used, and seems a shame not to reuse. Of course, I throw away old yucky stuff.

What in the heck does one use industrial grade H202 for?

I have used the Biosafe product for LECA treatment, but Physan @ 1 teaspoon/gallon or chlorine bleach @ 1 oz/gal works too.

50% peroxide is a great oxidizer. I was working in a manufacturing operation that made pigments for ceramic glazes, and we used organic flocculants to cause the powder slurry to clump up for dewatering before spray drying. If left in the powder, the viscosity of the glaze would increase with time, so we dewatered, stirred in some peroxide and it was completely degraded.

[YetAnotherOrchidNut]

Originally Posted by WaterWitchin

What in the heck does one use industrial grade H202 for?

One use is Rocket-packs: https://www.scientificamerican.com/article/rocket-pack/

It reacts explosively on contact with gold.