Hmm, I cant see any picture of what I think thoes are. But if a hydroid is in close relation to an anenome just like aptasia is, I used to have a lot of small anenome looking flower clusters with red mouths in teh center, the tenticles were clearish and the tops of the tenticles were white like little wild flowers. they were very small and pretty but I could tell each of them packed a sting just by looking at them. Mabe they are trying to reproduce again. I hope not I got rid of most all of them when I changed tanks, then with my copperband butterfly and the rock boiling i knocked it and the aptasia down to nearly nothing. Ohh well if thats what it is then i'll find out. Thanks!