Using of Hydrogen Peroxide for algal treatment

**bclee** · 17th May 2004, 10:25

I would like to gather feedback on using H2O2 on getting rid of algae.

1. Concentration of H2O2
Typically 3% H2O2 is available in pharmacies, anyone uses H2O2 of higher concentrations?

2. Algae type and effectiveness
What type of algae did you use H2O2 on? How effective was it?

3. Method
Did you squirt the H2O2 directly onto affected areas in your aquarium? Did you remove the object you are treating from the aquarium?

BC

**victri** · 17th May 2004, 17:07

1. Concentration of H2O2
I use the 3% available from pharmacies.

2. Algae type and effectiveness (I've tried H2O2 on the following)
- BBA: very effective. BBA turns white in a matter of hours.
- Green spot algae: moderately effective
- Brown algae (in-between glass and gravel): very effective

3. Method
- For treating gravel, syringe to squirt over affected area, then insert syringe just under the gravel and squirt again.

- For plants with little algae growth or hard-to-remove equipment, I use a syringe and squirt the H2O2 directly on the affected area.

- For cases where almost the whole plant is affected, I remove the plant and treat in a small tupperware of water. Again syringe is useful in targetting the affected areas. 2-3 hours after treatment, I rinse the plant and put it back in the tank.

Note: Plants with soft tissue sometimes do not survive the treatment and will melt. For tough plants such as Java fern, Chlorox/bleach treatment yields better results.

**Peng Kang Hill** · 18th May 2004, 08:34

Guys,

Sorry but this question may appear not too intelligent.

What do I say when I go to the pharmacy? H2O2, Hydrogen Peroxide? Any brand available?

What do say if they ask me what I want it for? Algae removal in my tank?

.. Peng Kang

**bclee** · 18th May 2004, 09:00

I tried H2O2 for the first time last night.

1. Concentration of H2O2
3% H2O2 from Guardian Pharmacy

2. Algae type and effectiveness
BGA: very effective (all the BGA was gone this morning)
BBA: moderate (BBA turned pale, but don't seemed to have totally died)
Green: not so effective (no much impact seen)

3. Method
Using a syringe to inject direct onto affect areas in the tank.

4. Problem

I got over enthusiastic on the treatment. This morning I woke up with 8 dead cardinal tetra.

The other fishes (ram, cherry barbs, otos) seemed to be ok. I guess I should have restrained myself to "attack" a small area at a time, rather than whacking the algae in the whole tank.

BC

**bclee** · 18th May 2004, 09:05

[quote:c46f79

19="Peng Kang Hill"]Guys,

Sorry but this question may appear not too intelligent.

What do I say when I go to the pharmacy? H2O2, Hydrogen Peroxide? Any brand available?

What do say if they ask me what I want it for? Algae removal in my tank?

.. Peng Kang[/quote:c46f79

19]

3% Hydrogen peroxide. Any brand will do. Normally used as an anti-septic.

Ask for "hydrogen peroxide", they will show it to you.

BC

**anaconda** · 18th May 2004, 09:38

I understand Hydrogen Peroixde is used for bleaching of hair normally.

It is suppose to be harmful to the skin. Any truth in that?

**bclee** · 18th May 2004, 09:40

[quote:0dc9849991="anaconda"]I understand Hydrogen Peroixde is used for bleaching of hair normally.

It is suppose to be harmful to the skin. Any truth in that?[/quote:0dc9849991]
Those used for bleaching hair is of much higher concentration, probably 20-40%. (Corrected... see below.)

3% H2O2 are used for cleaning wounds and can be applied directly onto the skin.

BC

**juggler** · 18th May 2004, 10:01

[quote:cb6c8ea372="bclee"]I tried H2O2 for the first time last night.

1. Concentration of H2O2
3% H2O2 from Guardian Pharmacy

2. Algae type and effectiveness
BGA: very effective (all the BGA was gone this morning)
BBA: moderate (BBA turned pale, but don't seemed to have totally died)
Green: not so effective (no much impact seen)

3. Method
Using a syringe to inject direct onto affect areas in the tank.

4. Problem

I got over enthusiastic on the treatment. This morning I woke up with 8 dead cardinal tetra.

The other fishes (ram, cherry barbs, otos) seemed to be ok. I guess I should have restrained myself to "attack" a small area at a time, rather than whacking the algae in the whole tank.

BC

[/quote:cb6c8ea372]

Cool. Can kill BGA some more. Maybe next time I can try this instead of anti-biotics.
BTW - do you think the H2O2 can destroy the hair algae sometimes growing among the Java Moss? What about brush algae?
About the fish death, how much H2O2 did you used in what size of tank when the casualty happened?

**bclee** · 18th May 2004, 10:54

[quote:8c34c59033="juggler"]About the fish death, how much H2O2 did you used in what size of tank when the casualty happened?[/quote:8c34c59033]

I think I used almost 200ml in my 60L tank...

My tank was bubbling with O2 after the treatment even this morning.

BC

**anaconda** · 18th May 2004, 11:06

Thanks for the clarification, juggler!!

if i wanna bomb the tank whats the dosage recommended? 3ml per gallon?

anyone tried that before? h2o2 bombinb the tank

**bclee** · 18th May 2004, 11:12

[quote:5a94b08e0e="bclee"][quote:5a94b08e0e="anaconda"]I understand Hydrogen Peroixde is used for bleaching of hair normally.

It is suppose to be harmful to the skin. Any truth in that?[/quote:5a94b08e0e]
Those used for bleaching hair is of much higher concentration, probably 20-40%.

3% H2O2 are used for cleaning wounds and can be applied directly onto the skin.

BC[/quote:5a94b08e0e]

I ran a check...

H2O2 used in hair bleaching is about 6% concentration. H2O2 will be harmful to human skin at concentration >8%.

BC

**bclee** · 18th May 2004, 11:15

[quote:22b9daf22b="anaconda"]Thanks for the clarification, juggler!!

if i wanna bomb the tank whats the dosage recommended? 3ml per gallon?

anyone tried that before? h2o2 bombinb the tank[/quote:22b9daf22b]

I think it might not be a good idea to "bomb" the tank. H2O2 is a strong oxidising agent. Too diluted it is not effective. If it is concentrated enough to be effective as an anti-septic, it can be harmful to animals. It is more suited to be used for localised treatment.

BC

**victri** · 18th May 2004, 11:36

bclee:
When the BBA turns pale, that means it's dying. You should notice that your shrimps (or SAE) will start nibbling at the dead algae the next few nights.

I haven't encountered any loss of livestock so far. In fact my shrimps and cories like to go play with the bubbles. I try to limit usage to at most 50ml for my 3ft for each treatment. Safer to treat the tank a little bit at a time.

One funny thing I noticed was that when used in a tank with ADA soil, even a little amount will cause a lot of bubbling, as compared to a tank with normal Lapis gravel.

Anaconda:
It's not so effective for bombing. It'll have to be in pretty high concentration to have good effect. We did try once when TanVincent was rescaping. Removed all livestock and lowered tankwater to few inches height, then poured in the whole bottle (500ml) to clean the glass sides and gravel. If the tank were to be full, we'd probably have to use 10 bottles. Most effective method is still to use syringe for spot-treatment.

If you leave it on your skin long enough, your skin will dry up and might start to peel. It doesn't burn or sting though. When I was young, we used it to bleach hair, but you need to leave it on for hours.

Juggler:
Best not to use it on any kind of moss. The moss will turn brown and die together with the algae.

I have this container where I grow a lot of BBA and hair algae (don't ask me why).

The algae is actually quite fascinating. They actually bubble when I leave the container under the sun! I'll pull out some and do a timed experiment with pics later.

**naturetan** · 18th May 2004, 13:42

Usually I used H202 just to clean algae on wood, by removing it and wiping it with cotton wool. For plants and tank surfaces, I do manual removal. Very effective I would say for BBA. Never encounter BGA, so not sure. Nanas and ferns will turn brown and die on that part which is touched by the solution.

FYI, H202 is not only good for wound cleansing, it's also an inexpensive and effective way to clean your ear and remove ear wax.

**cheeboonyong** · 21st May 2004, 14:38

never tried H202.

I typically take out the BBA infested driftwood/stone and just soak it in boiling water. Does the trick every single time. Of course, if there's moss/nanas/plants tied to the wood, you can forget about this method.

**Plantbrain** · 23rd May 2004, 13:44

Mmmuuummm ear wax

Wonder if it grows plants? Mix some KNO3 in with the wax and use in the substrate.

You will want to be careful about fish kills with H2O2 as someone here recently learned.
Preview the dosage first, it is a strong oxidizer like bleach.

Different tanks will have slightly different max amounts, but the same can be said for Copper sulfate also.
It really kills the BBA and makes your Crypts grow very well.
So says the best Crypt grower from the USA.

It's not a cure all, no such thing, just add enough CO2, nutrients and take care of the tank routinely.

H2O2 is mainly useful for spot cleaning a small amount of BBA etc. It's not really something for entire tank cleaning.
Some have tried it with hair algaes, some said it worked.
I tried it on two species and it did not work.
So I'm not so sure.
Dead fish have occured with at least one person anytime this thread gets brought up.

Regards,
Tom Barr

**victri** · 24th May 2004, 01:58

Just did my little experiment with some BBA and green hair algae. Put them in a bowl of water and added about 3ml of 3% H2O2. Not much difference observed for the first few hours except for the bubbling reaction. Next day, BBA had turned grey and hair algae all brown.

I'm guessing that the acidity level of your tank water might affect the reaction. I notice that when I use a little bit of H2O2 in my tank with ADA soil, the bubbling is much more intense and lasts longer, so if anyone is thinking of trying it, please be careful .

**cheeboonyong** · 24th May 2004, 13:52

For the people who tried it, did you have to switch off your filter/powerhead to stop the water current? I'm thinking: does it take time for the H202 to take effect; if so, then wouldn't a strong current dilute the H202 from the specific locality where it's applied?

**victri** · 24th May 2004, 16:07

If you're treating a spot where there's strong current, then you'll need to turn off your filter. You only need a few minutes for the reaction (bubbling) to take place, then you can switch the filter back on.