I'm with Greenbud!
Saying you don't have to feed a coral, regardless of type, reminds of the argument about fish "growing to the size of their tank"... The organism needs food man...
Now there's quite a bit of debate about what causes the coral to feed. Simply blowing bits of dust in it's path, and watching it's polyps close up, does not mean it's eating. I forget the link or where I read it (I think it was on the Reefkeeper's Discussion list), but some studies were done surrounding this, and it was found that far more than particle size is involved in corals selecting food. The quote that I remember was about flavored bits of plastic ground to the appropriate size, were injested equally as often as regular food. They however obviously weren't digested.
The mechanisms that queue the feeding response aren't 100% understood, either. Smell, shape, size, texture, and a whole bunch of other factors play a part in triggering the feeding response. I've seen similar actions by some LPS and anemone's in my care. They attempt to eat the offering, but after taking it partially into their mouth, they revers and spit the food back out. Guess those Silversides are too old. I hesitate to go so far as to say the organism's have Pallette's, but I've seen them reject a food one week, and than accept it the following.
Personally I think the best approach is to follow Greenbud's advice, and partially supplement the natural plankton one can get going in a properly maintained system. Phytoplankton really is the base building block of the food pyramid in the ocean, some say the Earth. It's also very difficult to maintain a constant culture in one's tank, as it's going to be consumed and filtered out faster than it can grow. Therefore IMO, the best way is to supplement it either with DT's phythoplankton as my first choice, since it's alive and will not foul the water as easily. My second choice is for the frozen cryopastes from BSD, however I find them easy to overdose with. One must be careful when using them. I have however found they are an excellent additive to any home-made food recipie. The Golden Pearls I also add to my home-food recipie, however haven't seen any conclusive information indicating that they are an accepted food substitute by corals. In other words, I could just be adding flavored bits of plastic to my tank.
I'd like to give a few links RE: where I read all this, but honestly can't for the life of me remember where. Perhaps those less abusive to their brain's had read the same threads, and will remember. If I had to guess, I'd say it was something debated by Toonen and a few other's on Reefkeepers, but I think that was a couple years back.
- Mac