Hello everyone, when i restarted my tank after a years of a break i messed up and got sugar sand as my substrate. I am wanting to change it out so that I no longer have sand dunes and I also have the base to thick. I do have my established snails, hermit crabs and emerald crabs I have to think about when making the change and I want to do it gradually so I do not mess up the ecosystem that much. I was planning on doing 1/3 of the tank at a time and right now I have a 55 gallon tank that I am working on. Any suggestions or should i just siphon out the sand and slowly replace it with special grade reef sand?