Water purifier for sea monkeys?

I love my sons sea monkeys and they are starting to breed. Does anyone know how you can put them into a big tank without killing them. I dont know what purifier to use. They say you have to use the sachet but surelly there must be another thing you can use.
I want a massive sea monkey kingdom !!!

(yes im a big kid lol)

what do you mean freezing the water. I dont get it??

I found this website on preparing your tap water for aquarium use that I thought might be useful to you: http://www.firsttank...

cheers odal