[mike31154]

To clarify my last, I actually use a rectangular rubbermaid style container that holds about 25 gallons to mix up my salt water. Often I allow it to mix with a small AquaClear powerhead in it for days, even up to a week. I use the empty salt buckets to lug the water from the basement to my tank when I do water changes. Been using rubbermaid tub for years now, it's caked with calcium residue from the salt mix & bulging at the sides from the weight of the water kept in it. No issues yet with my tank that I could remotely attribute to the use of this container.

For a container the size I described above, just make sure it's fairly robust. The first one I used had thinner sides & eventually cracked. Many of them come with lids. I drilled a small opening near the top of the container & run my RODI line to it via a JG fitting.