[Tahoe Reefer]

You can just add a bit of food if your looking to start the biological cycle. Damsel fish, which includes clowns, are very hardy and will often survive the initial cycle of a tank however, it can be done without stressing out any animals.
If i'm misunderstanding your post and your tank is already in mid-cycle, I'd advise waiting until those params come down before adding the clownfish.