In my 10 gal tank without skimming but an extremely heavy filter feeding population, it takes approxiamately 2 hours for the cloudiness caused by 2 cups of phytoplankton to disappear. I suggest that each hobbyist do their own observation and let that determine how long to leave the skimmer off.
Don't turn off water circulating pumps. That's how plankton gets to the coral! And actually the more (more not faster) water movement the better.
But Mike, why are you using a skimmer anyway? I know your tank. Your tank is too new and has too little for the coral to eat as it is. You really don't need to even consider using a skimmer for another six months unless you plan to add a lot of SPS coral.