I have just received some Chaetomorpha and Caulpera from a friend. ( wildeone ) and i was reading up on the both. Now i read that when caulpera turns white that it is going sexual and once it goes sexual ("leaves" disintagrate and release spores into the water), the chemical reaction in the water causes problems for the overall health of the tank. Any nitrates, and other nutrients stored by the caulerpa are also released back into the water. Now the Caulpera i received is not white, i was just wondering what i should do if it ever turned.

Does anyone know what causes this or a way to prevent it? Also once it turns white and goes threw its cycle will it really cause major problems?

There was a good article about this in Reefkeeping Magazine a couple of years ago.

http://www.reefkeeping.com/issues/2004-05/nftt/
(http://www.reefkeeping.com/issues/2004-05/nftt/)

I don't have caulepra but I have read that the key to keeping it from going sexual it to prune it regularly.