Results for bacteria in a bottle seem mixed. I wonder if people using the bottle just throw in the bacteria and nothing for them to feed on (no ghost feeding or adding bottled ammonia) Or if there's not enough ammonia and the bacteria just dies off and the cycling halts. I'm trying it for the first time to set up a quarantine tank but I will be transferring some of my existing bio media to it because I don't fully trust it. I used Brightwell for marine tanks. I may make a thread and see what results I get. Bacteria in a bottle wasn't a thing the last time I did tanks so it's new to me. So far I'm also still in the opinion that using existing bio media is the best and fastest way to cycle.