Beach pebbles/rocks

[Coasting]

Elementary school science!!!!
Drip some vinegar on it, does it fizz?


http://www.minsocam.org/msa/collecto...d/rock_key.htm

Most of the rocks we find around here in riverbeds are a pretty safe bet

[GoFish]

What are you planning on using these rocks for btw? Been there done that with beach rocks. Are you wanting more biological filtration? Or wanna use them as a substrate in your display?