i want to know what the benefit of hatching these are? each time you hatch them do they have to be replaced? or is it like phyto where you can split them and keep going? i watched the podcast on doing it and i would like to do live food but is it economical?

yes, it needs to be replaced. see they are brine shrimp, and they grow up. you cant keep them in there like you could phyto.

as far as being economical, yes, its very cheap. you can get the eggs and then you only hatch them once or twice a week as you desire

if you look at something like this
Premium Grade Brine Shrimp Eggs (http://www.brineshrimpdirect.com/c1/c2/Premium-Grade-Brine-Shrimp-Eggs-c12.html)
you can get 8 to 16 Oz of premium eggs (only get premium eggs) for less than $30 and these will last you a ling time since you only use 1 tsp per hatch

they can be cultured though right? just not as easy as phytoplankton.

if by cultured, you mean grown out, yes, but there's not much point..
after about 18 hours they nutritional value drops to near nothing

i am not aware of anyone who re harvests eggs from adult brine shrimp. i dont even know if its possible or worth while, the eggs are so cheap

by culturing i mean having a continuous cycle of shrimps. one hatch out, then let them go. i have been reading my Culturing Manual from florida farms :D. it doesnt seem practical for the hobbiest, but with a proper gutloading method the shrimp would still have a good nutrition value.

yes, you can, but as stated its not practical for a hobbyist

is that the same as doing the rotifers or is there a different process there? thanx for the info

no, rotifers are different, and can be cultured

here is a video outlining how to do rotifers
http://www.talkingreef.com/forums/podcast-episodes/648-culturing-rotifers-video-podcast-episode-42-a.html