H2O2 question for Randy

Reeferdood · Oct 13, 2016

Morning Randy,
I wanted to pick your brain on how hydrogen peroxide reacts with the water in a closed reef system. I have read so many posts about using it to help kill off dyno's and clear the water similar to ozone.
Could this be true?
In simple terms, could you please help me understand this?
Thank you.
Rick

Reeferdood · Oct 13, 2016

OOPS,
posted twice...

Cory · Oct 13, 2016

Good question. I beleive that it basically wants to attach to almost everything and thats why it burns things or kills them.

Randy Holmes-Farley · Oct 13, 2016

Hydrogen peroxide is an oxidizer, like ozone but weaker.

Both will tend to react with organic matter, including the surfaces and even internal organic molecules of organisms. With some small organisms, such as bacteria, that can damage and kill them if present in sufficient concentration. In larger organisms (like people), that will just irritate exposed tissues at sufficient concentrations. I'm personally not a fan of adding it except in desperation (such as with dinos) because of concern over the lack of specificity of effect.

The reaction with organics can reduce yellowing, but hydrogen peroxide is not nearly as efficient in this sense as is ozone. These oxidizers react with carbon-carbon double bonds that often produce yellowing, making product molecules that do not absorb light.

Reeferdood · Oct 13, 2016

Thank you very much!

Reeferdood · Oct 13, 2016

One thing that had me scratching my head was how long the peroxide took before breaking down and no longer doing anything.. Seems the general consensus is 1 ml per 10 gallons which seems like nothing in a larger system..
Does it take a while to break down or is it instantly done upon contact with the water?

Randy Holmes-Farley · Oct 13, 2016

Reeferdood said:
One thing that had me scratching my head was how long the peroxide took before breaking down and no longer doing anything.. Seems the general consensus is 1 ml per 10 gallons which seems like nothing in a larger system..
Does it take a while to break down or is it instantly done upon contact with the water?

The half life of hydrogen peroxide in natural seawater is measured in days:

http://publications.gc.ca/collections/collection_2014/mpo-dfo/Fs97-6-3080-eng.pdf

However, a reef tank with tons of organics (organisms, detritus, etc) will likely be faster. Maybe much faster, but I've not seen reliable data.