Here's my procedure.
I have a 3 gallon bucket from PetSmart. I fill it to the 3 gallon mark with cold water from my tap. *gasp* :lol: Then I kick on the power head, air line (for aeration) and heater. I watch the temp and when it gets somewhere close to my tank's temp I start adding salt. Once I get the salinity where I want it, I add in my pH buffer, detoxifying solution and any dosing. Then I let that sit for a few hours then I add it to the tank.
I'm not sure where the 24 hour method came from. I don't have time to wait 24 hours to let my water and everything mix. As long as everything is dissolved in the water then waiting 24 hours isn't going to mix it any more than it already is. :mrgreen: