Hi all, I’m really confused and need advice. I currently have crushed coral in my flu all evo 13.5g which due to a month in hospital the sand bed got so badly stained I can’t clean it and it looks gross. It’s a mixed tank with a clown, fire fish and 2 cardinals. I’ve ordered caribsea live pink Fiji but have read so many conflicting posts on what to do to swap it out. Should I do it a section at a time or all in one go, tanks been running a year. Please help!