Hi everyone, recently because of new development my surrounding area is being dug up. One area was excavated to 20m for a basement for a new house and they dug up a crap ton of limestone. Naturally i went and collected some thinking it COULD be some base rock for free lol. If anyone can tell me if it is safe or not i'd be very gratefull. It was dug up in the northern part of bloemfontein. Its definitely limestone i tested with vinegar, and its ligther than a piece of fiji rock of the same size i have in my tank.