mixing salt water

Up till now I was always under the impression it was best to leave salt water mixing over night before doing a water change but on the red sea pro bucket it says to mix for between half an hour and two hours and no longer than four hours ......is there Amy reason for not leaving over night??? And what's best????what do you guys do???

I use the normal red sea salt and leave it over night. Being honest i have no idea why it would matter considering it would be circulated in the tank the exact same.I mix cold overnight and throw heater in next morning.

How you mix is exactly how I've been doing it.....I may of over thought this but the only explanation I can think of for this is....you know the way the wave makers in your tank over time build up with stuff....coraline algea and such... is it possable mixing for too long some elements have already stuck to the bucket and powerhead and by the time I add to the tank ,I'm leaving those elements behind?????

Being honest i am not entirely sure but i would think some salt loss that will stay in the container as i always have a resadrew left over , bt as for any of the godness i imagine corals are needed to take this away.