I would say: well established tank with adequate bio-filtration, you can place right into the display but you do risk introducing unwanted hitch hikers such as mantis shrimps like ellisz said. You should take some existing tank water (ie: two 5 gallon pails, 3/4 full) and use this as a dunk or dip rinse prior to placing into your display. Your NH3
and possibly your NO2
levels might slightly rise for 1-3 days than fall back.
On the other note: if your display is relatively new (cycled within the last 6 months) or have minimal bio-filtration, then you should place the LR
into a container with aged water from your display with a power head and heater till the NH3