Hydrogen Peroxide

From RTAW Reefpedia
Jump to: navigation, search
Hydrogen Peroxide
Common Name(s): N/A
Molecular Formula: H2O2
Used For: Treatment of Cryptocaryon

Increasing ORP

Caution: Corrosive


Don't breath vapours

Avoid skin and eye contact

Material Safety Data Sheet: Hydrogen peroxide


Hydrogen peroxide is a strong oxidising chemical that can be used as a disinfectant or antiseptic (bactericide, fungicide) on fish and equipment. The degradation of H2O2 produces hydroxyl free radicals that can then rapidly oxidise any chemicals it encounters, changing the chemical into something else. On biological systems, it works by breaking down the cell membranes, leading to lysis and destruction of the cell. For algae, bacteria and protozoans this will lead to the death of the organism and in large multicellular animals (such as fish) the epidermis (skin surface) may suffer damage. However, hydrogen peroxide also acts as a stimulant to the autoimmune system by attracting white blood cells to the affected area and suppressing capillary blood flow in open wounds.

Hydrogen peroxide has proven effective in a number of studies at eradicating both free-swimming and attached stages of various parasitic protozoans (Cryptocaryon, Amyloodinium)[1] [2]. However, like copper based treatments, it is a bactericide and is harmful to beneficial bacteria.

Can be used as a bactericide or fungicide to treat surface infections of organisms.

Can also be used to increase the oxidation reduction potential (ORP) of a water or the dissolved oxygen content of water for fish transport [3].

Hydrogen peroxide will also oxidise harmful ammonia to nitrite and then to nitrate, as such in can be used to rapidly reduce the concentration of ammonia in a tank or bath.

The commercial product Medic contains peroxide salts.


As the use of hydrogen peroxide is still a burgeoning treatment, caution should be exercised as correct dosages for individual species is still in the development stages. Treatments should be applied in a hospital / quarantine tank.

The treatments below have been extracted from the published research papers, although these concentrations have proven effective with little to no mortalities, it is advisable to begin treatments at a lower concentration for shorter periods initially, working up to the higher levels over the course of the treatment. Heavily infected fish will be more susceptible to the negative effects of hydrogen peroxide. A well progressed infestation will have more of the fishes' underlying tissue exposed to the peroxide and this is likely to cause a greater level of irritation and potentially limit the capillary blood flow through the gills, a prime location for parasitic infestation. As an analogy, for humans this could be related to applying peroxide to a small cut being barely noticeable, however a large graze exposing a large area of tissue is going to sting.

As the treatment is applied over a period of 4 weeks, a lower concentration (e.g. 50ppm for 30mins) on the first application will reduce the severity of the infestation and provide an opportunity for the fish to regain vitality. In subsequent treatments the fish will be in greater health and better able to withstand higher concentrations.

During the treatment period, the fish must be kept under constant observation. Distressed fish should be removed from the bath immediately and allowed to recover before subsequent treatments are continued. The effects of hydrogen peroxide end almost instantaneously after the fish has been returned to non-treated water. For this reason the treatment is as safe as the attentiveness of the observer during treatment.

For others experience with using this treatment, see Talk:Hydrogen Peroxide


75 ppm for 30 minutes, repeated 7 days later. [2]


100 ppm for 1 hour, repeated three times a week for 4 weeks. [1]

Mixing a Bath

Using a 3% hydrogen peroxide solution, to achieve:

  • 50ppm, add 5ml per 3l of saltwater
  • 75ppm, add 7.5ml per 3l of saltwater
  • 100ppm, add 10ml per 3l of saltwater

Avoid using plastic containers, preferably glass. Do not aerate during treatment.

Reported Treatment Concentrations and Tolerances

Anecdotal reports on acceptable tolerances to specific concentrations have been obtained from members of RTAW Forums and the Talk:Hydrogen Peroxide here, the information provided here is to act as a guide when judging suitable treatment concentrations.




  1. 1.0 1.1 (http://www.ctsa.org/Upload/AnnualReports/2008AnnualReport.pdf): Center for Tropical and Sub-Tropical Aquaculture 2008 Accomplishment Report, CTSA: Hawaii, 2008, 73.
  2. 2.0 2.1 (http://icecapinc.com/informationcenter/articles/marine-velvetamyloodinium-ocellatum-a-discussion-of-this-disease-and-its-available-treatment-options): Marine Velvet/Amyloodinium ocellatum: A Discussion of this Disease and its Available Treatment Options, IceCap, 2008.
  3. (http://www.fao.org/docrep/009/af000e/AF000E00.htm): Berka, R., The transport of live fish: a review, European Inland Fisheries Advisory Commission Technical Paper, 48, 1986.