How soon will I have Nitrite problems Jon?

[Bob I]

The fish are now in their new home. I fed them some frozen brine today, but that was not appreciated too much. I also bought frozen bloodworms. They will probably be appreciated more. Should I pick up a Corydoras or two for the uneaten food? And how soon can I expect Nitrite problems? When it happens should I do big water changes until it settles down?