thats a good read. It reminded me of the creeks and streams near staughnton, east of terre haute a little ways. There are strip pits everywhere out there, me and dad fished them a lot, but the streams are all dark rust red from all the iron in the water! What do you use to seal it?If it's unsealed...sealed keeps it from leaching out. Also, somebody on another forum sent me a link that claims that limestone/rust/heavy metals do not leach out in alkaline waters(7+ pH). Here's the link he left me...
Suitability of Rocks in the Aquarium - A Practical Guide