Are you a midwesterner? We certainly have a lot of limestone here in WI!
Ive heard conflicting stories about this . On the one hand limestone is a softer rock so rain and water running over it will erode it into the water. On the other hand our water comes out of aquifers that are basically lined with limestone - so how much extra lime is your pond rock going to add to the water that isn't already there?
I used it around the edges of the pond with the bottom 6 inches of the rocks submerged in water - and it didnt cause any change to the water or higher pH. Water running over it as in over a falls might be a different story though. I believe some limestone is harder than others - so I would seek out those. I have some rocks that I threw away recently because they were so soft and breaking apart.
I do like the natural look of it - it blends nicely with WI landscape.
Yes!! It will look awesome in the pond. Recently I visited my cousin's place, where I found an interesting thing by installing Tiles in the Pond and near to the whole Backyard. It was looking tremendously attractive, that I couldn't stop myself from clicking the pictures. When I asked her about, how she got an idea, she recommended Zothex flooring Experts for giving such a unique idea. After visiting the site I came across Full Article and blogs where they have given lots of beneficial things about the Flooring.
I have watched nearly every aquasxape video and watch there clients spend tens of thousands of dollars on there preference of Weathered limestone. now Weathered when talking rock generally means rock that has fallen apart and is now useless. the Weathered they are talking is not smooth or fracture free it has character odd shapes cracks etc. I don't believe adding any lime stone that won't crumble in your hand can ever be an issue in a pond