Emily,
I waited almost 24 hours before doing a water change - wanted to watch the status of the eggs. Fish were pretty agitated, and the anemones all got antsy (and several began to wander), but the only things that really suffered were two trochus snails, which acted "stunned" for a couple of days before dying (I'd had them for 4-5 years). They were the only snails in the tank, so I can't say whether it was species-specific effect or not. Oh, that and the fact tha my GS Maroon clowns haven't gone back to spawning yet (they were spawning every 10-12 days like clowckwork before the spawning), so I'd bet your FO tank will be fine.
Kevin