Good thread. I have made and used
SW within 60 minutes and I have let it mix for a week. I have also pre-mixed it overnight by mistake when I have dropped in the powerhead, gotten distracted and forgotten to go back and dump in the salt.
I can't say that I have noticed any difference in the methods.
My preferred method is to dump water into my Brute, start the powerhead and then dump in the initial bolus of salt. I go back after an hour or so, check the SpG, add salt and repeat as needed. I prefer to let it mix overnight just because I cannot test for every element and I believe that some are slower dissolving than others. Why overnight? It's arbitrary.
I have found that the Rio 2500 that I use for mixing salt creates enough heat that I don't need a heater to get the water up to tank temperature unless I am mixing 20 or more gallons.
