Temp and Salt Water Questions

[Aquattro]

I keep mine at 76.5. Generally anywhere from 75 - 79 is good. 2 degrees swing is fine for fish or coral.
I mix my salt for a week, so not much help there. I'd let it mix with a good pump at least 6 hours, others might suggest longer

[Aquaticguy11]

I've heard from a few sources that keeping your temperature a little warmer (around 79F) is best for coral growth. 2 degree changes throughout the day should be fine, but keeping it as stable as possible is best. As for mixing salt, I'd keep it mixing for at least 24 hours. This will make 100% sure that everything has dissolved properly.