If you see one most likely there is more coming out soon. What you can do is manually remove all the newly hatch nudi, remove the egg ( their egg is hard to see though), dip all the zoas over and over again .. I find not all dip are effective against nudi, maybe other can share what type of dip is effective against nudibranch. The easiest way to spot nudi in your tank is use a blue torch light and shine on your tank when the light is off. The nudibranch will glow in color due to the zoa they end. It will be a long battle but it can be won over. Good luck and share with us your process here. Sent from Singapore Reef Club mobile app