What ppm hydrogen peroxide solution to kill algae/life on rocks?

[Miami Reef]

I’m going to dip my rocks infested with clove polyps in a hydrogen peroxide solution. I want to nuke all life on the rock so I can reuse it instead of buying and aquascaping new rocks.

What percent hydrogen peroxide, in ppm, is needed to achieve this? What’s the contact time?

I’d want to kill it in about 30 minutes to an hour, so it must be concentrated enough.

 

[cdemoss01]

12% hydrogen peroxide at 120,000PPM for 30-60 minutes should kill everything.

 

[Randy Holmes-Farley]

I’m not sure what levels are needed. The above post may be correct.

 

[Fish Fan]

For full eradication, why not bleach here? It's a much stronger oxidizer than H2O2, which I think you would need quite a lot of to complete kill everything on the rocks. Hydrogen peroxide is available at I believe 17% (vs. 3% typical household peroxide) used in horticulture, you could try something like that.

 

[Fish Fan]

Here's a 35% H2O2 for the food industry, but I still think 3 bucks worth of sodium hypochlorite would be better for what you want to do. The residual bleach can be neutralized by allowing the rock to completely dry out, and/or overdosing a dechlorinator like Prime.

35% Food Grade Hydrogen Peroxide Solution 1 Gallon

Efficient cleaning with our 35% food grade hydrogen peroxide. Safe for food contact surfaces, user-friendly, and environmentally responsible.

bulkperoxide.com

 

[Miami Reef]

I’m going to use bleach. I’m documenting the process in my build thread.

Thanks @Fish Fan for the bleach suggestion. I have sodium thiosulfate to instantly neutralize it.

 

[Fish Fan]

I’m going to use bleach. I’m documenting the process in my build thread.

Thanks @Fish Fan for the bleach suggestion. I have sodium thiosulfate to instantly neutralize it.

Glad I could help you for a change

Good luck!

 

[Miami Reef]

I bleached the rocks, but then I used tap water to rinse it out. It made me realize copper, if in the tap, could potentially saturate the rocks which could leach into the tank.

I bought a box of new dry rocks from the LFS.

 

[Fish Fan]

I bleached the rocks, but then I used tap water to rinse it out. It made me realize copper, if in the tap, could potentially saturate the rocks which could leach into the tank.

I bought a box of new dry rocks from the LFS.

Maybe that's for the best

I rinsed in RODI when I last bleached rocks (though I only had like 12 pounds at that time), then let them dry, then still did a round of dechlor in a bucket before placing in the tank.

 

[rishma]

I bleached the rocks, but then I used tap water to rinse it out. It made me realize copper, if in the tap, could potentially saturate the rocks which could leach into the tank.

I bought a box of new dry rocks from the LFS.

I would not have thought about copper.

What made you think about copper saturating the rock? Is there really high copper in your tap water?

 

[Miami Reef]

I would not have thought about copper.

What made you think about copper saturating the rock? Is there really high copper in your tap water?

Copper is known to bind to calcium carbonate. It behaves very similarly to phosphate in some ways.

I don’t know if my tap contains significant copper, but I know calcium carbonate has the potential to bind many metals.

Was the contact time low enough to not be a problem? Probably.

I still played it safe. Anyway, those rocks would still release organics and dying organisms even after bleaching it. It would take some time to neutralize the chlorine in the tiny pores, as well. I’d need to have a running powerhead with test strips etc.

It made more sense to buy new ones, especially since I wanted to finish the project that same afternoon.

 

[rishma]

I would not have thought about copper.

What made you think about copper saturating the rock? Is there really high copper in your tap water?

Copper is known to bound to calcium carbonate. It behaves very similarly to phosphate in some ways.

I don’t know if my tap contains significant copper, but I know calcium carbonate has the potential to bind many metals.

Was the contact time low enough to not be a problem? Probably.

I still played it safe. Anyway, those rocks would still release organics and dying organisms even after bleaching it. It would take some time to neutralize the chlorine in the tiny pores, as well. I’d need to have a running powerhead with test strips etc.

It made more sense to buy new ones, especially since I wanted to finish the project that same afternoon.

Makes sense!

 

[FishLvR]

I'd go straight to acid. Less time, cheaper. MORE FUN.

 

[Miami Reef]

I'd go straight to acid. Less time, cheaper. MORE FUN.

Haha. I like the way you think. I’ve got gallons of muriatic acid in my office for my different shenanigans. The skulls on the bottles just really make the place feel like home. lol

 

[Miami Reef]

Fun fact. Did you know hydrogen peroxide can neutralize bleach and vise versa?

You’d assume two oxidizers would compound their effects.

 

[FishLvR]

Fun fact. Did you know hydrogen peroxide can neutralize bleach and vise versa?

You’d assume two oxidizers would compound their effects.

I think I did. I am not 100% sure but doesn't that make a deadly gas?

 

[Miami Reef]

I think I did. I am not 100% sure but doesn't that make a deadly gas?

Just oxygen, water, and table salt. lol

Mixing certain strong bases and acids can release toxic gases. It really depends on the exact compounds, but you generally shouldn’t be mixing them without prior research lol.

 

[Bandit69]

For full eradication, why not bleach here? It's a much stronger oxidizer than H2O2, which I think you would need quite a lot of to complete kill everything on the rocks. Hydrogen peroxide is available at I believe 17% (vs. 3% typical household peroxide) used in horticulture, you could try something like that.

I second bleaching them. Then pressure wash all of the junk out ofvthem