SaraJean asked a question about peroxide...

[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.

[isurus79]

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.

I wish we could pin just this post in this forum and then just refer to it anytime someone asks a question. Case closed.