What is this?
 

Ok my reef tank is about 5 months old now and I noticed something new in the last couple of weeks that I would like to know the name of ....

Little round bubble growths .... they are clear to blueish ... like marbles only smaller... any ideas

re bubbles
 

if there like mine, people have been saying its due to lack of water movement, could be wrong though!!!

Do they feel really hard? Could be single bubble macro algae.

Sounds like bubble algae

http://www.saltcorner.com/AquariumLi...php?GroupID=84

Just felt one... they are hard....

Yes... TY / looking at the pictures I would say that they look like Valonia macrophysa / there are only few ... should I remove them and what is causing these to apear all of a sudden?

Thanks

If you remove them just try to scrape underneath so they don't pop as that'll spread it. Live rock can have hitchhiking macro, it's common and normal. If anything the barren tanks people run are the oddities.

Well I removed them... they were actually quite easy to remove.. however I did manage to pop one .... hopefully my skimmer will be effective in cleaning up the spores... I will watch for these carefully and remove as I see them / I believe they must of come in with live rock like you suggest as I recently put in a piece with some coral that I purchase recently.... funny thing is I never had any problems with any nuisance critters till I through that rock in with the rest of my live rock work... I noticed a couple of apista anemone that I had to exterminate that apeared on that same rock...