SAFE use of hydrogen peroxide to solve problems


Staff member
RC Mod
The knowledge of this substance is spreading: before somebody nukes their reef with it, let me explain what it is and how to use it. The reason I do this here in the newbie forum is that YOU guys have rock that can be moved, before it gets grown into a reef, and before a 'little patch' becomes a monster problem.

Hydrogen peroxide is 'almost' water, but the 'almost' can kill things. Regular water (h20) is two hydrogen atoms with one oxygen. Hydrogen peroxide is h202---two of each. And that extra oxygen can burn heck out of your corals and critters. OXI-dation. Burning.

OK. But can you use it to kill pest patches on rock?
Yes, at the strength commonly sold at the drugstore.

What will it take out? Just about any living tissue that absorbs it. Particularly patches of caulerpa weed, xenia, gsp, or other stuff you don't want. I would NOT recommend it for aiptasia unless it's the only one you've got. This is a nuclear option, of sorts, and it's too easy to get into overkill.

Here's how to do things safely. First of all, wear gloves, wear glasses or goggles: let's not have any splash, but let's not court Murphy's Law, either.

Pour a small amount, enough to cover the bad spot, into a small CERAMIC or glass bowl. Wearing gloves, remove the rock with the problem, scrub the problem with a non-medicated old toothbrush, then submerge ONLY the problem patch in the h202 for 30 seconds. REmove the rock, toss the h202, and rinse the rock with a cup of ro/di, holding it over the sink. It will likely bubble and fizz. It will not hurt your kitchen pipes.

REplace the rock in your tank and for extra kill, put the 'bad' side down into the sand and just revise your rockwork to accommodate that. You will still see bubbles of oxygen coming up: do NOT let those bubbles hit anything living, like corals. Don't let your fish mess with it. Here is a very important thing to know: THis is not just 'air', which is 90 percent nitrogen and other gasses besides oxygen---this is pure oxygen, which can burn. Got it? Be careful. Rinse until you're sure it's ok, and know that it may bubble for a while, even so, so don't set it under your prize coral.

Be careful. If you pass this advice on, pass ALL the advice on, including the protection and the cautions. Little patches are easier to eliminate than massive areas. It's a tool and a useful one, but like a chain saw, not to mess with carelessly.
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