I usually make my FW up with a pH buffer, ie, i add the pH 8.3 buffer to RODI water. Then I place that container in my sump to allow it to warm. This usually takes a bit of time, but it is worht it. My whole dipping procedure usually takes about an hour.
A healthy coral will be stressed, but it will survive, one that is not or is infested with something might not make it, but that is good, you dont want disease in your tank.