I’m looking to do some DIY cave rockscape, but need to start with a custom base/shape. I was originally looking at ceramic or clay, but then remembered a product I had once used in a dart frog enclosure, called Great Stuff. It’s advertised as water proof and pond safe, and I had no issues with the frogs. Has anyone used this in a reef? I didn’t have luck finding a previous thread, though the term “great stuff” brought up quite a few results… Any thoughts or advise would be wonderful