What is this? ...wierd growth on macro

[Kronk]

Thanks that makes sense. The reason i was questioning whether it was an egg sack is cause they always seemed to be around bits of chewed on caulpera.

[christyf5]

It could be that the "chewed on" part has become damaged and no longer retains any of the green pigment and is now white? Thats what I always figured on mine, either that or it was gearing up to spawn or whatever caulerpa does.