Hydrogen Peroxide for Algae Removal

It was not to long ago brought to our attention on the board here that Hydrogen Peroxide can be used safely and effectively for a partial fix to algae outbreaks.

There is no OVERALL cure for Algae outbreaks without hitting the source of the problem but the use of Peroxide can help combat some of the larger outbreaks WITHOUT tearing down your tank.

Warning - Following this method CAN pose risk to your fish. Understand that adding anything to your tank you take that risk! I did loose a few Cardinal Tetras because of my dosing but I would have lost them or more by moving the fish to another tank to break down and clean my tank!

Keep in mind that Hydrogen Peroxides chemical makeup at an elemental level is "H2O2" When it breaks down it coverts to "H20" and "O" (Water and a single molecular of Oxygen) which is MUCH safer than the Copper method of removing Algae as neither are poisonous to livestock.

From what I have read, Algae's Cellular Structure is MUCH LIKE Bacteria... We all know Peroxide is a pretty good antibiotic, with that mentioned that is HOW it kills Algae.

There are 2 methods to using the peroxide and I will touch on each way.

Spot Treatment
I started with this method because it does pose as high of a risk as the next method but will not treat some forms of algae! This treatment method seems to work best in my experience with Blue Green Algae.

Take a syringe (with no needle but the ones that you can use to feed baby birds and administer medicine to children) and fill it with Peroxide. Put your had and the syringe in the tank and spray it onto infected surfaces.

You should notice instantly that the algae starts to bubble! That is good! The Peroxide is breaking down the Algae cells and releasing Oxygen!

The next day it should be gone but if that area was bad enough it may bubble for a day or 2 after.... once the bubbling stops the Algae should be gone

(note this DOES NOT WORK on Beard Algae!)

Tank Dosing Method
This has been a successful method for removing Beard Algae as well as Strand Algae.... Although there have been issues with dosing (Both Anthony and I need MUCH higher than recommended dosage to destroy the Beard Algae)

Dosing Directions:
This is the safe range - 1-3 mL per gallon
I lost some Tetras in this range but the lower amounts did not clean out the Beard Algae - 4-6mL per gallon

Apply to tank before lights out as Peroxide breaks down faster in light. Also if possible lower your filtration flow rate or cut off your filters for the night shortly after adding the peroxide (give it some time to mix through your water first)

Keep in mind the higher the dose the higher the likelyhood some of the more sensitive fish in your tank may die. Start with lower doses first and work your way up after you know the lower dose is not enough because the Algae is still alive after a few days (normal color).


How to know when Peroxide killed the Algae
Because I have only dealt with 3 forms of Algae I can only remark on them
Blue Green Algae - Bubbles and then disappears after a day or 2
Beard Algae - Does not really bubble but turns reddish after 1 day and after a few more days starts turning white and into fish food.
Strand Algae - This turned from the brownish color it is to bright cherry red and then to white in about the same timeframe as the Beard Algae.


Peroxide is commonly used by some advanced aquariusts when the Oxygen level is low in the tank (also another reason to keep Peroxide around)

Good luck if you are reading this to control your own algae problem!