bob965;4919577; said:You removed much of your bio-filter when you changed the substrate. Your tank is going through a mini-cycle. Do water changes and dose with Prime.
How long has your filters been running on this tank. I recently changed over my 55 from gravel to sand. All new sand and water. My filter is old and been running for years. I did not go through a mini cycle at all. Most of your bb is going to be in your filters. although bb is on every thing in your tank most of it will be in you filtration.