I don't know if anyone is giving them away for free but I got my kit on amazon for $8 (https://www.amazon.com/gp/product/B00439I1NW/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1). I hatched mine in a critter keeper filled with 1 Liter of spring water. I am moving them into a 7-gallon tub in a few days. I think the rule people stick to on here is 1-2 triops per gallon water.

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Edit: Link