Hydrogen Peroxide to control ORP. Bad idea?

[srjosepz]

I started to use ozone to control the ORP value of my tank, as it was over 238mv. I can keep it at 370mv easily with the ozone, but I can smell it a little I am very close to the aquarium, even after the carbon filtering. So, I am asking myself if the ozone can be replaced by hydrogen peroxide, adding just small quantities to keep the ORP about 350mv , with an ORP controller.

I know ORP don't is affected by Hydrogen peroxide as fast as ozone do, and the effect ill keep some time after stop dosing it, so, adding it with a peristaltic dosing pump controlled by an ORP controller, in a save margin could help...

Any of you uses hydrogen peroxide only as ORP control way, or am I talking nonsense, and Its only "safe" use is occasional — to treat a pest or disinfect frags at high doses , and not long term low doses use?

 

[Randy Holmes-Farley]

I do not have any reason to think higher ORP is better than lower ORP when it is controlled by chemical additions.

Hydrogen peroxide often lowers ORP in tanks since it can also act as a reducing agent.

 

[srjosepz]

I do not have any reason to think higher ORP is better than lower ORP when it is controlled by chemical additions.

Hydrogen peroxide often lowers ORP in tanks since it can also act as a reducing agent.

Really? Thanks for the answer. I never thought hydrogen peroxide could act as a reducing agent under any circumstances... so, i was talking nonsense :beaming-face-with-smiling-eyes:. I I’ve checked the water circulation, the skimmer sizing, the accumulation of organic matter, and nutrient input, and I haven’t found any reason for such a low ORP. I only have two small fish, about 6 or 7 cm each, in 600 liters, and I had never seen the ORP go above 250 mV until I started dosing ozone.

 

[Randy Holmes-Farley]

It is known to reduce copper 2 to copper 1 in seawater, and most folks note that it drops ORP. :)

 

[srjosepz]

It is known to reduce copper 2 to copper 1 in seawater, and most folks note that it drops ORP. :)

I am confuse... I did a rapid test with one liter of salt water from the aquarium in an external container. I put the ORP probe in this water. The value (as expected) was the same as it was inside the aquarium, 350mv Then I added 2 or 3 drops of hydrogen peroxide to the container. In less than 20 seconds, ORP changed from 350mv to 165mv.... :anguished-face: as the answer before (THANKS again) said it could happen.

In a try to know more about ORP I read several articles about the concept... but ORP isn't an easy thing to understand... my first thought was that the cause could be the fast oxidation of all that could be oxidized in this water due to the hydrogen peroxide addition, because some articles say, (Or I thought understood) the ORP isn't an indicator of the water quality or ability to oxidize nothing by itself, but should be an indicative of the relationship between reduction and oxidize process in environments with both substances present. I mean, in the case of reducing or oxidizing agents fall bellow of a certain level, the ORP value will be low. Because there is not much to oxidize or be reduced. This seems to be sense on my mind, and this is a good parameter to be measured in environments like reef tanks where both agents are added.

BUT then, I added ozone to this water, and... ORP went up. So, ORP must be an indicator of the ability to oxidize, as other articles say...even (or with more reason) if there are no reducing agents present. Tap water, by example, have a high ORP value with no reducing agents dissolved, due to chloramine or any other oxidant...

But this principle don't work with hydrogen peroxide... so it depends on the oxidizing agent too? Hydrogen peroxide can reduce copper2 to copper1, but ozone can't? What is what ORP measure, the oxidation potential of the water, or the relationship between oxidation and reduction?

Too much info at time for my limited mind... :beaming-face-with-smiling-eyes:

 

[Randy Holmes-Farley]

Ozone is purely an oxidizer, but hydrogen peroxide can oxidize or reduce, and in seawater, it reduces metals which are likely the thing that directly impacts an ORP probe. :)