Safe Shale

[philfista]

Hi all , I have a load of purple/blue looking shale chips . The stuff you put around the garden , comes from Jewsons. It looks really good and i was thinking of putting some in my tank . Would this stuff be a problem ? You can get different colours so maybe its dyed .

Anyone know ?

 

[darkwolf29a]

Can you put shale into an aquarium?

I know you can put slate in, but I'm not sure how stable shale is.

 

[celaeno]

there's two steps of testing to see if shale is safe.

using vinegar or another acid (api's nitrate test bottle #1 contains 41% HCl), apply a few drops to the shale. if it fizzes and there're little bubbles appearing, it will raise the ph of the water.

soak it in a cup or bucket of warm water overnight. if there's the slightest bit of oil on the water surface in the morning, it's unsuitable for aquarium use.

in my experience, shale usually fails both tests, so is unsafe.