This is what I have been using the last two years. Very dependable.
http://www.ebay.com/itm/260888446841?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
Mike
We have the same thing on two of our SPS (Green acro & Ice fire) doesn't seem to hurt anything. Looks like a small feather that comes out, turns and goes back inside??
I have read the TOTM page about five times. beautiful beautiful beautiful tank!!!
And the nice thing about it is, it's a mixed reef. The ballance of clean and dirty water.