Thank you for the thoroughness of your response. I will try to suggest some things to do differently that I think will improve the environmental-nutritional issues your CB may be facing. They are my opinions and suggestions. But before I do, I would like to say that your routine and care is very good. I think there was a 'blip' in their care when you were away and their well being was in someone else's hands, less knowledgeable or unable to keep up the quality care you were giving. This happens to me and others, too.
Probably the biggest environmental impact was your absence and the changes that occurred then (as noted above).
Your tank is still settling in. The addition of rock to an established aquarium is a bit of setback to the aquarium's aging and settling in process. On paper your tank might be 6 months old, but some may argue it is really only 2 months old (when you added the last LR and it cycled again).
With your diligent and frequent water changes, I would question the need for the use of the additives. You may need to add Ca and Alk, but other than that, the fresh/new salt water will provide all the trace elements you will need. You may be overdosing those (and wasting your $). You may want to read up on this perspective:
http://reefkeeping.com/issues/2004-05/rhf/index.htm
You didn't mention that your refugium has any macro algae in it. I believe in the therapeutic effects that growing macro algae has for the fish.
So, under the heading of environmental I see a tank not settled yet and in a state of change; your absence and reduced care for a time; and perhaps too much trace elements. I would suggest focusing on stabilizing your water parameters; letting your tank age more; don't put it in the hands of an amateur; stop adding trace elements; and perhaps make sure you have some healthy macro algae growing (in your refugium or main display).
Regarding nutrition, I see a significant deficiency here. (I am only addressing the CB, but you need to analyze your feeding relative to the needs of your other specimens.)
You are feeding a mundane, routine food that needs improvement. You should also be feeding more, with supplements. Your CB is an omnivore. It needs to have at least 40% of its diet contain vegetable matter.
I also don't clearly see that you are supplying extra fats and vitamins to the food.
Your feedings should be no less than twice a day, three if you can manage it. Smaller, more frequent feedings is what your fish and its digestive system is used to.
Regarding nutrition, I would suggest the following:
Think of a weekly feeding regime. There are 21 feedings. 5 of those feedings should be frozen Cyclopeze, frozen mysis, or frozen fortified or live fortified brine shrimp. Every other day, put a piece of algae in the tank, anchored at the bottom, for the CB to munch on and pick at throughout the day.
Feed pellet or flakes for up to (and no more than) 5 of those feedings. I would vary the kind, choosing herbivore flakes now and then. (See below on why 'herbivore').
On the remaining feedings, mix and vary the diet of commercially prepared
frozen herbivore and angle foods. The reason I suggest this is that because most of the commercially available herbivore foods contain more fish protein then they do vegetable matter. Read their label and you'll most likely see that spirulina or kelp is third or fourth on the list of ingredients, behind krill, fish meal, and other carnivore foods. So, the 'herbivore' food is good for an omnivore, actually.
Now: Once a day, soak one of the feedings in a vitamin for fish. Once a day, soak one of the feedings in a fat source for fish. Don't soak the Cyclopeze. It is a high fat source on its own. Below are just some suggestions. You can find others.
Vitamins & Fats:
Vita-Chem
Selcon (fats)
Selco
Zoe
Zoecon (fats)
I think that if you can manage to implement the above nutrition and environmental changes over the next few days, your CB will improve. As for your other specimens, the clown and chromis will also eat the same diet as the CB. Others should be targeted for what they should be eating.
Start with small feedings, and slowly increase the quantity. Let the Nassarius snails & conch do their job.
Our fishes can be trained to eat almost anything (look at how many tangs eat fish flesh!). But, that doesn't mean they
should be eating those things.
BTW, congratulations on NOT having any hermits in your aquarium!
I hope you will find the above helpful. Ask if you have ?
