Been working with PK shrimp for the past 7-8 years now - this is what I learned about stocking strategies with direction from Cody and Travis and through many trials [and errors!]:
Fisheries with sufficient macrophytes established prior to predator stocking [only FHM/GSH forage present] we stocked 250-500/AC. For fisheries with established predators [and macrophytes] present we doubled that number to 1000/AC. For fisheries lacking habitat [macrophytes] regardless of fishery present we strongly encouraged not to invest in PK introduction until habitat could be established. By following these guidelines a self sustaining population developed in every project in which I was involved within a season. In some cases [due to low qty of PK available] I've achieved this with as few as 50 adults, but the population took longer to establish, as one would suspect. Hope some of this is helpful.