Garden Pebbles

[NickBFC]

I have found 3 nice looking pebbles in my garden. I have scrubbed and soaked them in hot water. If I place them in a bucket of tank water to test the PH, are they safe to use if the results are okay?

 

[ColR1948]

Test with a spot of vinegar, if they start to bubble then no, if not they should be OK.

 

[fluttermoth]

If it doesn't raise he pH, and they don't have any metallic veins in them, they should be safe.

You can try the vinegar test, but vinegar isn't really acid enough. Rust remover, if you have access to a bit, is much better.

 

[NickBFC]

Thanks, not conclusive enough results so think I'll stick to picking up some slate