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Peroxide to kill algae


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#1 Guest_mshi_*

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Posted 15 February 2007 - 09:54 AM

I have read in some of the posts that using about 1oz. 3% peroxide per 10 gallons can help kill algae. I have a low tech (heavily planted) set up with limited water changes. The tank is set up about 6 weeks and I am starting to see some hair algae on some of the plants. My question is does the peroxide then dissipate over time or in this type of set up is a water change recommended after peroxide use. If it does dissipate, how often can it be used. Also as peroxide is used to clean wounds I am assuming it kills bacteria. If so can it affect the biological filter.

#2 Guest_fundulus_*

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Posted 15 February 2007 - 10:49 AM

View Postmshi, on Feb 15 2007, 08:54 AM, said:

I have read in some of the posts that using about 1oz. 3% peroxide per 10 gallons can help kill algae. I have a low tech (heavily planted) set up with limited water changes. The tank is set up about 6 weeks and I am starting to see some hair algae on some of the plants. My question is does the peroxide then dissipate over time or in this type of set up is a water change recommended after peroxide use. If it does dissipate, how often can it be used. Also as peroxide is used to clean wounds I am assuming it kills bacteria. If so can it affect the biological filter.


The peroxide will definitely dissipate soon (I'm not exactly how soon). The peroxide has a stronger effect against unicellular organisms with lesser ability to protect themselves enzymatically, so I'd expect some bacterial damage. But it's a balancing act that way, I guess, as to what's the lesser harm.

#3 Guest_drewish_*

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Posted 15 February 2007 - 10:53 AM

I'm not a planted nor an aquarium expert but I personally wouldn't start using peroxide quite yet.  You are going to have algae in the beginning stages of setting up a tank.  I would try to resolve the problem causing the algae instead of removing the symptoms.  Another option would be to add fish such as Florida Flagfish that would consume the hair algae.

#4 Guest_nativeplanter_*

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Posted 15 February 2007 - 12:11 PM

View Postmshi, on Feb 15 2007, 09:54 AM, said:

I have read in some of the posts that using about 1oz. 3% peroxide per 10 gallons can help kill algae. I have a low tech (heavily planted) set up with limited water changes. The tank is set up about 6 weeks and I am starting to see some hair algae on some of the plants. My question is does the peroxide then dissipate over time or in this type of set up is a water change recommended after peroxide use. If it does dissipate, how often can it be used. Also as peroxide is used to clean wounds I am assuming it kills bacteria. If so can it affect the biological filter.

Peroxide breaks down soon enough that I have used it daily for about, oh, maybe 4 or 5 days straight.  It will kill bacteria, but in a soil substrate there are far more bacteria than the peroxide can kill before it is broken down.  Since your tank is heavily planted, the plants should remove a good deal of the ammonia even if the biological filter is not up to speed for a couple days.  I've never had a problem with ammonia when using it.

#5 Guest_Sean H_*

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Posted 25 February 2007 - 07:23 PM

The peroxide you buy at the grocery store(~3%) will break down on the order of a couple minutes or less depending on aquarium conditions(i.e metals,pH, hardness, organics, ect.).  Like it was said earlier, treating the symptoms is not usually the best approach.

#6 Guest_nativeplanter_*

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Posted 26 February 2007 - 03:07 PM

Treating the symptoms can on occasion be the best first approach if the algae is covering the plants.  This can be especially true for cyanobacteria, which can smother plants such that they might as well have been locked in a dark closet.  Of course, nutrient control would certainly need to follow to solve the problem in the long run.

#7 Guest_mshi_*

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Posted 03 March 2007 - 09:08 AM

View Postnativeplanter, on Feb 26 2007, 08:07 PM, said:

Of course, nutrient control would certainly need to follow to solve the problem in the long run.

What type of nutrient control are we talking about in a Walstad low tech type set up. Would some carbon in the filter for a while be a good idea? Tank is up 2 months and I am getting some hair on some of the leaves and the water has quite a yellow tinge.

#8 Guest_nativeplanter_*

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Posted 03 March 2007 - 11:42 AM

Nutreint control in planted tanks usually requires phosphorus control.  Unfortunately, for the aquarist, many public water supplies have added phosphorus to help control corrosion in the pipes (thus lowering lead content in the water).  If you have public water, you might want to call the water department to ask if they know the phosphorus concentration and if they add additional phosphorus during treatment.  

If phosphorus is added, the problem is that it is in a form that isn't easily used by plants, but IS easily used by algae.  The other problem is that filter additives like "phosban" don't seem to absorb it (it even says on the label that it isn't for use in such water).  The best solution I found is to use DI or RO water.  Aquarium Pharmaceuticals makes a DI filter that is the most affordable I have seen.

Once the algae is killed (by peroxide), the phosphorus is in a form that plants can use more easily, and can be absorbed by filter additives.  

Lastly, reducing light can help, if your plants can stand it.  A heavily planted tank helps too, which you already have.

#9 Guest_TurtleLover_*

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Posted 06 March 2007 - 12:17 AM

If you do use the peroxide, be careful because the peroxide can be detrimental to some plant species.  What types of fish do you have in your tank.  Another way to cut down on the excess nutrients in the tank is to cut down the amount of food you are feeding them.




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