I Sand

[nurglespuss]

Just to clarify, as others have said it is rare (though icreased by depth, and being undisturbed etc.).

Basically, if your maintaining your aquarium well, and move the sand regularly/don't have too thick an old layer etc. it should be absolutely fine to stir it up.

 

[StandbySetting]

Most of the toxic materials in anoxic substrates oxidize to harmless forms as they diffuse upward through the better-oxygenated levels, so get "neutralized" or rendered harmless before they hit the water column itself. The tank problems from such tend to be from disturbance to the substrate, from fish or from fish-keepers - which releases toxic stuff before it is oxidized by digging or stirring up such areas.

This sums it up perfectly, it's pretty much what I said in my first post, they're rendered harmless instantly, the most toxic of the sulfides H[sub]2[/sub]S is very reactive, it is oxidized instantly on contact with oxygenated water, which is present in the first few centimetres of substrate anyway, it's deeper down that there are lower levels of oxygen, the oxidation will have begun to occur in the top few centimetres of the substrate, the only possible problem is oxygen depletion, but this is highly unlikely as the quantity of gas in relation to water is very small, and any oxygen that is depleted in a given area will be replaced almost instantly due to diffusion and water circulation.

There is simply no need to disturb it, as afore mentioned any accidental gas disturbances wont cause problems in aquariums, unless you're implementing a deep sand bed in which case Oxygen depletion may become an issue.

 

[nurglespuss]

any accidental gas disturbances wont cause problems in aquariums, unless you're implementing a deep sand bed in which case Oxygen depletion may become an issue.

Exactly, thats what I was saying.

 

[StandbySetting]

Oh ok, good, glad I understand now.

 

[nurglespuss]

He he, see, genioseseses we are