the amount of time a fish is in a system, wether it be a stocker trout, steelhead.. or salmon really doesn't matter, hunger sets in almost instantly, the thing to try to key in on is the amount and nature of the food in the new enviroment, if its a muddy pond, a leech pattern is going to slay, if its a mountain lake at 3000 ft, most likely a san jaun worm or flying ant patterns gonna slay. Start with pink, if pink doesn't work the fish have begun to aclimate and switch over to natural feed, at this point emtomology starts to come into play. Hares ear beadheads and tiny prince nymphs rigged in a truck and trailer fashion behind a crystal bugger will almost always produce.