my algae wont grow!

[sma11s101]

I have a new tank cycling with live rock from both the lfs and from PA. The lfs stuff is nice and covered in this very pretty fuzzy algae which i think is caulerpa mexicana, but i could be wrong. Its growing like crazy, doubling in size every day or 2 which i dont really mind seeing as its pretty and theres nothing else in there at the moment. I also want it established before i get my clean up crew. At the moment its growing on everything, the rock, the sand, the glass, the thermometer... just not my other live rock. The rock from pa has NONE of it growing on it. Just some of the diatoms left over from the little bloom i had. Is there anything i can do to make the rock more habitable? perhaps scrub it?

on second thought i dont think it is mexicana, its really not that big. its only like 1/2 in long, tops, but looks very similar.

[graveyardworm]

Any chance you can post pics? Otherwise it could be any one of a number of different alga. Check this (http://saltcorner.com/sections/guest/algaepage/algaepage.htm) link and see if anything looks familiar. Also check the pics in this article (http://reefkeeping.com/issues/2006-09/reefslides/index.php).

[sma11s101]

I found it on that slide show and it says its Bryopsis. It also says its a pest but i dont really mind it. I just wish it would grow on my bare live rock. It seems content growing everywhere else, so i cant imagine whats wrong w/ the rock. it will even grow right up to the edge of the rock, just not on it.

[graveyardworm]

Its not bad as long as it stays where you want it, but this is unlikely as it does have a habit of eventually growing everywhere. When all the rock is bare its probably OK, but it can smother corals. The reason may be that it enjoying something particular in the rock its on, trapped nutrient sources perhaps.

[sma11s101]

okay, thanks for your input. I was wondering what was feeding it seeings as there are zero nitrates/phosphates.