A few months back I converted my fiancée's 10 gallon to a salt water tank and as she requested I put in a black sandbed. I would love to swap out the sandbed I have in my 40 breeder to black sand but I'm afraid of causing a cycle and losing some livestock. My question is this: would it cause any sort of harm to my corals or fish if I put a few handfuls of black sand in my sump every week and slowly swapped out the old sand for the black sand?

