I want to turn a 55 gallon tank into a deep sand bed refugium/sump for a 120. I'm still in the planning stage but I want to move the DT upstairs right above a 55 gallon tank that I'm using as a QT right now. The DT has been running for years without sand and I want to see more life that can't live without sand. So I want two DT the 120 upstairs without sand and a cool looking sump downstairs. Wondering what's the best way and time to do this? Should I start the 55 now as it's own system? Or add it in when I move the 120?