I believe this is a good thing...

[kmw0004]

I have a whole bunch of tiny red featherdusters popping up in my tank! Some were on some of the peices of rocks, and now they are spreading to other rocks. I also just now noticed a couple of bug like things on the rocks! That got me really excited, as well as the coraline algae that is popping up everywhere. My yellow button polyps seem to be multiplying really quick... I have only had them a month and there is already another polyp on an adjacent rock. They aren't going to take over the tank, are they?! Also, does anyone use the product called Purple Up?

[travie]

The yellow polyps are definitely a fast spreader, so they could possible take over a large portion. Just try to keep them contained to the area you want.

Haven't used the Purple Up.

[kaybee]

The tiny red featherdusters are among my favorite hitch-hikers. Very pretty.

[Amazon]

the bugs are amphipods. They are good. The feather dusters are cool to. I have one probably about 2.5in. long and many other small ones. It sounds like your tank finally hit the time of goodness where corraline gos crazy and corals spread fast. The yellow polyps are fine. i have some now and they do spread fast but I think its good. it makes a really natural look. If you dont want them just frag em and sell em.