Donald Kerns wrote:
They compete with the biobuggies for the ammonia and nitrite. Also seed
the tank with biobuggies so you don't have to start from scratch.

In that case, I'd just slowly add your population of fish and keep an
eye on the NH3 and NO2 levels. A new fish or two (depending on size)
every three days or so. Should be fine.

Donald,

I did add a carbon filter from my old tank and dumped it on top of
the filters in the cycling tank. I added about 3 pints worth of
old tank water and a stone bridge from my old tank.

I've now added my two fish. They seem happy, but I have noticed
that the ammonia had risen this morning. The levels are low, but
detectable. I will be doing a water change to even those levels to
0 later.