Thanks guys. Her enclosure is built like a tank. It is heavy as well already. Sitting on the floor because it is so heavy and huge. The water area is ranforced with 4x4s and the sides of the enclosure. The reason I am going to fiber glass most of the bottom is I want to place rocks and other things under the fiber glass to give it shape and contrast. Want to keep it relatively easy to clean as well. I learned a lot from the top part. Spray foam is wonderful but I think this will seal up better and if it does I will redo the top part. I am also making a area where she can go from the top to the bottom and it will be smooth rocks going down under the fiber glass. Just wanted to make sure it was safe to use. So far I haven't heard much negativity and wanted to see if anyone here had any experience actually using it.