[Woohoo, Jon's gonna have a new reef!
I mix up my saltwater in whatever container I'm using to collect the water. Trash can or 5 (or 6) gallon bucket.
I really like Kent's Sea Salt and have been very happy with the reaction my reefs give me. Everything dissolves completely. It takes 1/2 cup per gallon, roughly. You might have to add a little more salt to get to 1.026, or add a little more RO/DI water to bring it down to 1.026.
Btw, I think I saw you ordered/bought a refractometer last night. :
: Very good decision. (This coming from a guy that didn't use one for 4.5 years, but now loves it!)
As soon as the salinity and temperature match my tank, and the water it absolutely clear, I use it. You can mix it several ways:
Big pump (Rio 2500) to circulate the water. It will mix up 5 gallons in 5 or 10 minutes.
Small powerhead. Same principle, but takes way longer.
Stirring by hand. Hey, it works. Heals all those cuts on your fingers and arm, btw.
Mxing propellar on a cordless drill. This is a great method to mix and aerate water in under 5 mins flat.
Some people like to age their water 24 hours, even putting an airstone in the container to oxygenate the water thoroughly. I tried this myself, and after testing saw zero difference, and don't do it anymore.
When I do mix large amounts of saltwater (30 or more gallons), I let it mix with the Rio 2500 over night. You can put a heater in the barrel to get it to 78 degrees if you like, but I usually get about a gallon and put it on the stove to bring it near to a boil, and add that back to the bucket and mix. That is one of those things you just get a feel for. And if you overheat the water, icecubes will bring it back down.
Are you going to have fish that dig in the sand? If not, add all your sand at first, then some water, then your LR, then the rest of your water.
If you are going to have burrowing fish, put some LR on the glass, add more sand around it, then more rock, more sand, then your water. This will prevent your rockwork from shifting.
Others have put large PCV pieces on the glass and balanced their LR on the PVC, with sand everywhere else (even in the PVC 'feet'), so the rockwork will stay in place. I put my LR on the sand myself.
When adding your water, put a large platter on the sand (or trashbag) and add your water slowly to avoid a sand storm. Your LR will help settle the sand over a period of a few hours as well.
When you turn on your pumps, some sand will blow around, but as it matures over the first couple of weeks, it will being to 'stick' to the rest of the sand, and not move about much.
Got the SCWD hooked up too?]