Are These Safe To Use? How To Test?

[MermaidMel]

I bought a bag of large white pebbles for the garden that I never used, how can I test them to know if they are aquarium safe (although suspecting not, as they appear quite chalky/dusty inside the bag)

 

[jacko32]

put some vinegar on them if they fizz there no good

 

[MermaidMel]

I've only got malt vinegar.... don't laugh, can I use it?

 

[jacko32]

I've only got malt vinegar.... don't laugh, can I use it?

i dont see why not its still acidic

 

[james_fish]

Yes, you can use malt vinegar. I've done it.

James.

 

[MermaidMel]

Cool thanks guys