I have a 180gal tank that's been down 5+ years. Its completely empty of water due to evaporation but still has 350#'s of rock and 3" sand bed that has hardened. I replaced all the bulkhead fittings and ordered new pumps and replaced the fittings on my refugium. But I'm kind of lost on how to soften up the sand and getting rid of the white line on the glass where the top layer of sand touches the glass. I really hope that I can reuse the sand and rock without having to replace it. Can someone please help me?