Right now I have a good bit of lava rocks in my 125 but wanted to change it up. I had picked up some that looked good but after soaking/cleaning it seems like there are rust spots. I really like the look of the rocks in the picture but have no idea what type they are. I like the clean look and how algae would look on them. I was also hoping this would make cleaning a bit easier with the rocks at that size. As opposed to moving around lava rocks