Cool. When did they hatch? Mark it on the calender and then watch for the next batch of eggs to be laid. Then keep track of when they hatch. This will allow you to predict the exact night to turn off the pumps and prepare to collect larvae
Sorry, but I have to ask, Are you certain what you saw are Clownfish larvae. IME, people sometimes mistake Mysid shrimp for little swimmy fishies. Larvae move in short jerks and Mysid swim smoothly in little circles/figure 8's, often swimming around under rocks, in the corner of the tank, and sometimes a few inches up the side of the tank and back down.