How safe is Hydrogen Peroxide?

[Barry Tetra]

I get enough of this hair algae issue and want to use Hydrogen Peroxide to kill them.
Should I remove fish first or is it completely safe at low dose?

 

[fishyfun&fans]

Think logically a moment peroxide is in bleach would you put that near a fish

 

[xxBarneyxx]

Honestly even if it is safe it will only be a short term fix and you will be having to do it often.

Hair algae grows back really quick so you really need to fix the source of the issue rather than just treat the symptoms.

Is the tank new or still going through the cycling process? Ammonia in my experience is one of the main causes of hair algae. If you are cycling your tank and have ammonia in the water then this problem will eventually take care of itself once the tank is cycled.

The second most common cause of hair algae is phosphates. If the tank is cycled and been running awhile check your feeding regime. If you are feeding frozen foods make sure you defrost and rinse them properly before adding them to the tank as they can be a large source of phosphates. If you are feeding flakes or pellets make sure you are not over feeding.

Other than that check your lighting cycle isn't too long, make sure you are doing water changes and removing decaying organics (fish poop, food and decaying plant leaves for example).

The best solution is lots of live plants. Floating plants like duckweed are great at removing excess nutrients from the water column. It can take a little while for the plants to get established and really start doing the job so until then the best way to deal with the hair algae is to remove it by hand with a small brush (like a toothbrush).

I have the same issue in my new tank because the substrate I use leeches tons of Ammonia to begin with. Now my plants are starting to grow in and the filter is starting to cycle it is slowly burning itself out and going away.

 

[fishyfun&fans]

Maybe put fish in separate cycled tank then bleach this one out but then do a full cycle again on the one you’ve bleached before putting your fish back in it?

 

[Barry Tetra]

Is the tank new or still going through the cycling process?

It happens on 3 tanks that is already cycled, the only place where they grow is on Helanthium tenellum carpet.

 

[fishyfun&fans]

That way you can be 100% sure it’s safe

 

[xxBarneyxx]

It happens on 3 tanks that is already cycled, the only place where they grow is on Helanthium tenellum carpet.

Have you checked your water parameters (including phosphate)?
How heavily planted is your tank?
Are you dosing any ferts or using an active substrate?
What kind of lighting are you using? Photoperiod length?
Photos of tank setup?

You will quite often get algae growing on plants that are not doing very well. As the plants die off they start to decay and the algae uses this for growth. It could also be that you need a bit better waterflow in that area.

Helanthium tenellum I think is supposed to be fairly hardy and easy to grow but that doesn't necessarily mean that is applicable to all tanks. Dwarf hairgrass is supposed to be fairly easy as well but I have always found it can be a pain to keep until it gets established. Different water parameters might mean that even an "easy" plant can struggle in some aquariums.

 

[Barry Tetra]

Have you checked your water parameters (including phosphate)?

Nope, out of test kit atm.

Are you dosing any ferts or using an active substrate?

Ada aquasoil and sand capped with gravel.
I have tried pure aquasoil, doesn’t work out so well.

What kind of lighting are you using? Photoperiod length?

20 gal with Chihiros a series

Photos of tank setup?

Algae happens after moving helanthium from this 2.5 gal to
this 20 gal, already cycled...

 

[xxBarneyxx]

Ahh is it recently planted? Did you disturb the aquasoil quite a bit in the process?

If so its probably leeched quite a bit of ammonia again. ADA aquasoil is great for growing but is a massive pain for this. If you disturb it a lot it tends to cause a bit of an ammonia spike and a hair algae outbreak. Lots of water changes and removing the hair algae manually will sort it but it can take a little while.

This photo was my tank about a week ago. Hair algae caused by new ADA soil. Removing it all completely and it grows back in around a week.

Now though it's starting to settle down and the hair algae is pretty much gone. I expect it to show up a bit again when I add the rest of the plants and disturb the substrate but it will burn itself out eventually.

Chucking a few floating plants in for a little while will speed it up as well.

 

[AbbeysDad]

Hydrogen Peroxide is H202 - notice the base part of H20. It quickly becomes relatively inert when it contacts water.
I have used it successfully in treating dreaded black beard algae by removing affected pieces and spraying with hydrogen peroxide, letting it dwell for a couple of minutes, then rinsing the plant or decor in fresh water and returning the piece to the tank.
So it can be used safely, but I wouldn't be dumping it in the tank water.
As others have pointed out, the problem needs to addressed at the root cause. Reducing nutrients and/or light (intensity or duration) is the usual remedy for algaes.

 

[Ichthys]

H2O2 is sometimes used to treat parasites. There’s even a commercial disease treatment that is H2O2 (Waterlife Paragon). So it’s quite safe in small doses. It breaks down very quickly in water.

 

[Barry Tetra]

Hydrogen Peroxide is H202 - notice the base part of H20. It quickly becomes relatively inert when it contacts water.

Does that means O2 kill algae? How does it works exactly?

 

[Ichthys]

Does that means O2 kill algae? How does it works exactly?

H2O2 kills algae (and external parasites) before it breaks down.

 

[Myraan]

It's believed O2 was originally extremely toxic to life when photosynthesis first changed the atmosphere. Those organisms that survived it had an evolutionary advantage, and some of them eventually ended up using it.

 

[Stan510]

It can kill fish. The problem is the user starts with low doses..gets some results and then tries more.
It's only safe on plants that can be removed- and of course more effective that way so to make it worthwhile.
Like the others said...if conditions in the aquarium are the same..the algae come right back.