I have a small pond with shelves on each side for plants. Unfortunately Raccoon's keep tipping them over. Yes I know, who would think we have Raccoon's in Phoenix? Well we do, clients have the video to prove it. My thoughts for a fix is to get some cinder block or masonry type chimney pipe and plant in it I'm hoping it is heavy enough that it is too much work for them to tip them over. No fish in the pond yet but want some soon the question is will the block leach out enough toxins to kill fish? The pond is small so the block will consume about 5-8% of the ponds volume. I have a bog for filtration so it is a "naturally filtered pond" we have had fish & it all worked fine but its been without fish for a while. I don't believe it will be a problem but this lady's grand kids will be naming fish as soon as they see them and it will turn into a big problem for me if they turn into floaters. The fish not the grand kids... well I guess that would be a problem too but, nevermind.