Hi, I was wandering if I can put dragon stone in saltwater. I want to build a lagoon, I have a 29 gallon freshwater that is cycling. My mom won't let me do 3 tanks only 2. I love cichlids but I also want to do a saltwater lagoon. I have a 55 gallon saltwater already and will upgrade to a 90. I would do the lagoon in a 20 long. I did have a filterless 10 gallon nano that was beautiful.