I purchased some river rocks from a local landscaping store in order to use them as decoration in my fish tank. I tested them with white vinegar and after there was no reaction I cleaned all the rocks in a bleach solution. I followed directions from an online tutorial in order to do this. I am now in the process of making different structures by connecting rocks with silicone. My question is how do I make sure that the rocks and silicone are safe before adding fish to the tank? I got a generic all purpose silicone recommend by a youtuber who uses it in his tanks.