Just made this article for another forum!
A tep by step kinda guide. Goodluck
Acclimating Marine Critters
Everyone loves bringing home a new specimen, however excitement can soon turn to disappointment if you do not fully acclimatize your species to the water in your tank.
All individual tank parameters vary in one form or another, well beyond merely temperature and pH, so it is vital you take specific care to ensure your specimen survives when transferred.
Several methods can be used. One of the easiest is pouring. A slower, but more thorough method is drip line acclimation.
Pouring method
Acquire a measuring cup, 1/2 cup should be adequate; I use smaller. Slowly add half a cup of tank water into the specimen bag every ten minutes for the next few hours. The bag volume should double. Remove 50% of the water in the bag and repeat the process. You can repeat this process a number of times.
This could be considered erring to the side of caution; however I prefer to be careful.
Drip Line Acclimation
Gather a stool, chair, or another object lower than your display tank. I use a “Chilly Bin†(foam insulation box) as the Kiwis call it or a Tupperware container. Prop the bag and its inhabitants safely on the stool. These can be picked up at your LFS for free, or found at a camping/tackle store.
You should require about one meter (three feet) of airline tubing, more to be safe or if you plan to use the floor! Start a siphon through the tubing, and use an air valve to limit the flow of water to a slow drip, about one every second. Follow the steps above, by removing 50% of the bag water when the original water doubles, and start again.