I down sized to a nuvo a few months ago and took the rock, live stock and about 20 gallons of water. Filled the rest with new water. Also added new sand. I just realized as I'm typing this I was running biopellets on the old system. I started with a little patch of gha. I started to remove it by hand and uped my water changes. 5 gallons once to now twice a week. Started to change gfo and carbon once after water change and still was spreading. I am dosing vibrant 4ml a week. It is going away in some areas between the manual removal and cuc. Now it looks like I may have some dinos. I'm going to post a few pics any suggestions are appreciated.