there really is one thing I would like to stress here, and that is to not try and change too much for these carpets when observing changes in their postures, as these changes happen almost whimsically. They seem to be bothered by the most inane changes, like the switch of a bulb, which the OP has noted for all of us. I think it more likely the SWITCH ITSELF from 14K to 20K has caused the difference in behavior noted. My guess is the opposite change (from 20K to 14K) would likely have caused a similar result. Not an invalid inquiry, in the least, from the OP. And as fishy_clown pointed out, being shallow water species they are naturally found in very warm color temperature light. So providing a 10K bulb is almost always going to provide more PPFD at a spectrum these carpets are used to in the wild - with little question. I would guess that a plurality of the more successful SPS keepers keep their tanks under bluer light but that doesn't mean SPS prefer cooler temp lighting or do better under it. JMO.
Many folks, after reading threads such as these, might feel the need to replace their bulbs to warmer temp light for their gigs when observations come in like these. That is what I would like to discourage. Not the sharing of opinions and/or experience. No one keeper's experience are more valid/important than any others. It is the sharing that makes this site what it is. I hope the OP doesn't go out tomorrow and make yet ANOTHER lighting change, to warmer light.
Some food for thought is that IME, new additions are so mercurial that making changes in an attempt to "fix" something when a gig changes posture is never a good idea. And I only say that because I have been there, and done it, to no avail. How many threads have there been about reefers doing everything under heaven in an attempt to "perk up" their new gig.
I would like to know what ballast taylor t has been using for the results that he/she has seen. Take for example the XM 400W bulbs, I just tried out. You would think that the 15K bulb would produce more PPFD than a 20K bulb since it is a warmer temp light. But on an M59 ballast, that is not the case, oddly enough.
Edit: It would be nice to understand if the bulb changes and less vigorous posture are in fact correlated with less PPFD, but we can't know this since we don't have a ballast for taylor.
