the rock says...
the drip method is the best way to acclimate new items, you put all the items you are acclimating into a bucket at the base of your tank and run a small (1/4") tube from the tank that reaches short of the bucket. you tie a loose knot in the tube so it will slowly drip the water in, once you start the flow from the tank down the tube. the items can be kept together in the same bucket usually for some time without fighting. you just pour the item and the water from the bag into the bucket and then start the drip, make it drip fairly fast, but only drip, this will slowly allow the fish or invert to acclimate to the new water conditions, and then just pick them up with your hand or net and place in the tank and they will be used to new conditions, it takes a lot longer than the conventional method but is a sure way of acclimating them properly