Well....I guess it's a bit late now but next time you want to acclimate please read or ask before you come home with your purchase so that you are well prepared and know what you are about to do. Otherwise the bag may end up floating for hours (not good) before you receive an answer
You may want to do the "drip" method:
- Float the bag in the tank for a good 20 minutes to adjust for temperature.
- Take the bag out of the tank and pour out the contents (fish and water) into a clean plastic bucket. Preferably the bucket should be brand new
and designated strictly for your tank.
- Take a piece of air line tubing, tie a knot at one end, put that end in the bucket. The other end place in your tank.
- Start a siphon by sucking the end with the knot.
- Once water starts streaming into the bucket tighten the knot to a point where you have the water "dripping" 3-5 drops per second into the bucket.
- Maintain this drip rate until the water level in the bucket has basically doubled and then pour out enough water to the level you initially started with in the bucket.
- Start the siphon again but this time loosen the knot a bit so you can get a slow trickle of water pouring into the bucket. When your water level in the bucket has again doubled pour out again (like before).
- Lastly, start the siphon again but this time loosen the knot completely so that water pours normally into the bucket. This last step will basically ensure that the water temperature is equal to your tank's. When the water volume has again doubled (or even tripled) you are ready to net the fish and place it in your tank.
- Close the lights in your tank and put the fish in. (Just the fish, no water from the bucket)
I leave my lights closed for the day and then turn them back to normal the next day.
The total acclimation should last anywhere from 1-2 hours with inverts being acclimated even longer 2-3 hours.
This is how I do it. So far, so good.
Good luck
acclimation 
