And dip those zoas that are closed. If the others are open those should also be open. Look them over carefully with a magnifying glass (I use a 50mm lens from a 35mm camera system turned around for excellent magnification while wearing goggles for protection incase the zoa squirts) for nudies and nudi eggs or other irritants. Place them in a good flow area.
I recommend placing them in Kent's iodine after the bottle is floated to tank temp. Place enough to cover the zoa into a plastic deli cup, place the zoa in for 1 minute, shake the zoa off and place into good flow area.
note: keep the bottle upright while bringing the iodine to tank temp just incase cap leaks.