What you are experiencing is not a bad thing, trust me, it's a very good things. Skirts/tentacles that seem to elongate/become stringy as you eluded to, means only one thing, always has and always will, they are extremely happy. A zoa or paly that arrives to a new home that seem colorful, happy, healthy etc, could have had everything they wanted and need in their prior home, and they just never reached their true potential. It's not lighting, in my experimentation with increasing and reducing current, providing that a good light source is already present, flow has always caused my palys to lengthen their skirts. Excess current delivers more food/nutrition. Even though they are photosynthetic, current plays a major role in a happy, healthy, more robust appearance. How do I know this? I'll try to find the post a few years ago, but I placed a few colonies in direct line of a medium high oscillating current. True enough, the skirts began to lengthen, not overnight, but several days to weeks as I recall. I then move them to a new spot, same level, but now the current was low, not even medium flow, barely moving the polyps at all. True enough, in time the skirts began to get shorter. Again, this is most noticeable with Palythoas.
There are often times when that is not the root cause, but simply a characteristic of that particular morph. Some palys will have long skirts no matter what climate they are in, providing it's not a horribly kept system, it's just their nature. So much has been spoken of their hardy abilities to adapt, that we forget that zoas and palys can be very finicky. There are times when everything in your tank can be perfect, I mean lighting, parameters etc, and some zoas and plays simply will not open, and nothing is wrong. There are other reasons for retraction, but it doesn't relate to your question. Have you ever noticed that one days your skirts are very long and a few days to a week later, they just don't look the same. Often we jump to the conclusion that something is wrong, but I can assure you, there are times when absolutely nothing is wrong. Bottom line, they have bad days just like we do.
Stunning macro shots with great color capture BTW.
Either way, I wouldn't lose a moments sleep over it. It simply means you have a great set up, most likely a very mature one I'm assuming. Am I correct?
Good Luck my friend.
Mucho Reef
PS, I agree with you % 200 Celeb Kruse
