When I mix new saltwater in buckets, I pour it back and forth 3 or 4 times and then immediately add it to the tank. Never had a problem doing it this way. I don't worry about pouring cold saltwater into a warm aquarium because the larger body of water quickly absorbs the temperature difference and because in the wild, currents of different temperature water passing by are the norm. The animals can handle it. 

Same goes for Alk and Ca levels in the new saltwater. I never test new saltwater and here's why. 

The reason we change a small portion of water is to reap the benefit of adding correct levels of all the elements, not just Alk and Ca. Every animal likes the positive difference that a small percentage of new salt water adds to the environment. If there is an unusual variance due to a bad batch of salt, the larger body of water should easily absorb any difference. Sure, sometimes animals react to water changes but they come back within minutes or hours. If the animals cannot handle slight variations, there is probably something else not quite right with tank conditions, which unfortunately, leads to a proverbial tipping of the scale. 

SPS? Are you kidding? Most SPS grow in the surf zone where they get pounded by waves, cold and warm currents, downpours of fresh rainwater, and hours of sitting out of water in the hot sun. And don't forget tumultuous monsoons and typhoons. 

I'm wondering if we ought to be asking ourselves, "Are we babying our coral to the point that they can't handle a little change or tumult?"

Aloha,

Mark