Acclimating Amano shrimp to brackish water

[sirdarksol]

So I got a few Amano shrimp from the pet store.
I put them in a bucket and set up a drip to acclimate them to the brackish water in the tank. The drip was slow, and I allowed it to run for several hours, likely tripling the water.
This morning, my wife and I were watching them play in the tank, now, about three hours later, they're all dead on the bottom of the tank. It's not just the shells, (had that scare before).

They were the first critters to go in the tank, so it wasn't ammonia or anything that killed them.
All I can think of is that I didn't take long enough to acclimate them. Over what time span should one acclimate shrimp (or any brackish animal, really) to mildly brackish water?

[Chief_waterchanger]

Salt content should be gradually increased over days, if not weeks to properly acclimate shrimp.