Hydrogen Peroxide and Bristlenose


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Apr 7, 2021
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So, a few weeks back I lost an albino BN pleco I had just added to my tank. Initially I was concerned my Bolivian Ram killed it (more here), but he has been super docile with the remaining fish (cory cats). No aggression, it even seems like he likes to eat with them.

I recently read something about how BN plecos do not tolerate H2O2. My tank was set up with a large piece of driftwood. The wood was too big to boil, so I treated it with an H2O2 solution, letting it soak for a few days. I rinsed it off before putting it in the tank, but nothing more.

He had been in the tank for about 2 days and seemed fine, mainly cleaning the glass. Then I woke up one morning and he was expired under the wood. The location didn't seem relevant at the time because it seemed normal. This was approximately 4 weeks after I set up the tank. This recent information has me thinking I may have/had H2O2 retained in the wood. I've since pulled the wood from the tank and it is soaking in water.
  • Has anyone encountered this before?
  • Does anyone know a sure fire way to eliminate H2O2?


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May 8, 2019
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Lawrenceburg, KY
It is possible the hydrogen peroxide soaked into the wood, and as the Pleco was grazing, he sucked up a lot of it and died.

H2O2 is not only toxic to Plecos, but most other fish.

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