"Caulerpa species will suddenly die, releasing nutrients quickly into your tank that raise the ammonia, nitrite, nitrate levels and all sensitive corals and fish suffer....
Ok, so we all agree that this is fact?
First, I think we all might agree that any organism that dies in a closed environment and is not removed before it decomposes will cause a change in that environment. When we read a thread where this has happened in someone's tank, we need to consider the amount of mass involved compared to amount of volume of the tank? Consider a small anemone fish expiring in a 120 tank. Then, think of the difference with a large puffer in a 45 gallon system?
With Caulerpa species, many let it grow until it is a very large mass in it's enclosed system. When it dies, problems occur...
Is it just the decomposing tissue that causes the problem or does the alga release some toxin that adds to the problem?
What causes the organism to die? I think it could be multi-factorial, but in my system, I have always been able to trace it to a nutrient deficiency. When I first started collecting different species of algae, I found a really cool C. peltata: A gorgeous lime green color and a growth pattern that stayed low. I used it as a foreground plant and it covered around 1/3 of the front substrate. I noticed one day (after this tank had ran for quite a long time and had incredible growth rates) around an inch of this alga turn white. I did not think much of it, the thing was growing like a weed so any part that died would easily be replaced, right? Wrong! The next day the entire colony was white, decomposed and gone forever. Remember, this tank is just part of a 250 gallon system, so it was very small mass in total. I did have lots of other algae that could absorb the ammonia so the only tragedy I experienced was losing the species....
But, I had been testing the system and was able to watch the NO3 level go to undetectable levels.
So, I also believe that the above statement is fact, except for the word "suddenly". I had levels of zero NO3 for quite while before it died. I think it actually starved a slow death?
The cool thing I have learned about Caulerpa species is that they do warn me before they die, allowing me ample time to correct the deficiency before I lose any more specimens.
How can this relate to a reef type tank with a macro filled sump? It is a great species for anyone with a high NO3 level, to bring those levels quickly down, but once they do, they need to be harvested way down or replaced completely with slower growing (and slower consuming alga).
But, for those who also have a high PO4 level, it is possible to manipulate the elements to bring it down too.....
That is just one species, though. I have found really interesting things about other species. I now have around 30 species, a few different genera. Which would you think is the one I can't grow? Actually a very common one....
i dont like caulerpa either, i dont really like macroalgae in my display tank at all, only refugium.
