| | Re: Daphnia
How big is the tank, 454? And how many larvae in it? Without knowing this, how in the world could we even begin to answer your question?? Salamanderman's answer is sensible, but if you have a large tank and a lot of larvae it might be reasonable to put them all in.
If you don't put them all in, you need a separate (largish) container, and you'll need to feed the daphnia to keep them alive and nutritious.