Adding more fish to a recently cycled tank

[Toasted Tyrant]

My new Fluval Edge 46l has finished cycling (fishless) and I have started stocking it with cardinal tetras. I wanted 5 but the assistant in my lfs said I should only take 3 to start with.

How can I tell when it will be ok to add more? Do I just keep up the water tests and check that ammonia and nitrite stay at 0 for a couple of days?

 

[librarygirl]

Yeah, that should be fine. If you cycled it fishless with ammonia you should have more than enough of a biofilter to handle the full load of fish; actually you'll want to do this sooner after the fishless cycle ends rather than later b/c over time the bacteria will adjust down to the level of fish you have in the tank. So test it for a couple of days and if nitrite and ammonia stay at 0 then I would say it's OK to add the other fish. For a 12 gal though I'm not sure cardinals are the best choice long-term as they can grow up to 2" and are pretty active.

 

[Toasted Tyrant]

Thanks. I had wondered about the size of the cardinals. I expect that I'll be getting a larger tank in the next 6 months. At what size should I move them? 1.5"? How quickly do they grow?