ORP decreasing after dosing hydrogen peroxide?

cb684 · Dec 3, 2015

I just dosed 1 mL of hydrogen peroxide (3%) / 30 gal for the first time and the ORP went from 330 to 245. I was expecting it to go up... I have a ORP probe from Neptune Apex and apparently works ok, decreasing as pH increases during the day and increasing as pH decreases at night.
Any known reason for the drop after dosing hydrogen peroxide?

Reefing Madness · Dec 4, 2015

Randy Holmes-Farley · Dec 4, 2015

I've heard of this before, but I'm not sure why. It might free up certain metals or redox active organics that impact ORP, or maybe stabilizers in it are having some effect.

brandon429 · Dec 4, 2015

id enjoy seeing rebound data, how long it takes to average back to where it was as well.

cb684 · Dec 4, 2015

About 3 hours.

brandon429 · Dec 4, 2015

wow that's nice thank you
in our p threads other anecdotal info was suggesting it had a short dwell time but that might have just been observable effect time. nice to see the mv level details. I sure would have liked to have seen this on Russ' sps tank overdose, 250 mls 3% into 250 gallons, more than once

it was a rather purposeful attack on dinos which also side documented more fascinating details about bacterial response (non) and other things about the coral. orp trending there would have been gold. if one ml did that in your tank 1/30th, id be curious to see 30 mls, I know you wont be checking that in your tank with that kind of gear in tow we'll just have to see Russ' follow ups~

Russ' OD was the highest sustained id ever seen in an sps tank and provided valuable ecosystem tracking info/pics

cb684 · Dec 4, 2015

I just added another thread to discuss the use of hydrogen peroxide. Do you have the name of that thread or a link so I can share on that one too? I am looking for more input from other people. I do not think I saw that thread on my google search.

brandon429 · Dec 4, 2015

http://reef2reef.com/threads/reef2reef-pest-algae-challenge-thread.187042/

this is the one im working on here, collecting current day before and after shots. We don't study the chemistry much, I find it rather complicated~ what we do is simply study trends among poster submissions using repeating patterns of application, hope this helps, thanks for the input above

I don't think any of my peroxide threads would be chem helpful, just a bunch of pics and trying to repeat algae reduction patterns is 100% the intention. simply a bunch of web posters studying up/posting outcomes on a newish reef tool. Russ' thread is in there linked.

cb684 · Dec 4, 2015

Can you get the title changed and add the word hydrogen peroxide? It would help a lot to find it.

brandon429 · Dec 4, 2015

Yes I thought of that mos ago Ill find out who the mod is for that section and send it, agreed.

Randy Holmes-Farley · Dec 4, 2015

FWIW, if you killed any organisms, and they spilled their internal contents, that could lower ORP, but I would expect at least a small rise on the addition followed by a drop.

Also, hydrogen peroxide can induce biological responses in seawater (such as spawning) which might lower ORP:

http://www.sciencemag.org/content/196/4287/298.short