I chekced with my local Ace Hardware store to see if they can get stock tanks and the answer is yes. There are a couple of choices and Rubbermaid is not one of them. Tuff Stuff makes a 180 gallon tub with a 24 inch depth and a 160 gallon tub with a 21 inch depth. I'm also waiting to hear from a company called miller that also makes stock tanks to see what their 150 gallon tank dimensions are. I actually prefer the Rubbermaid 150 gallon stock tank, but I have not been able to find a dealer so that I can mitigate shipping costs, about 2/3 of the cost of the tank.
Most nearly everything I've read so far indicates that the minimum depth for fish to avoid stress, spooking, and so on is 24 inches. I prefer the 160 gallon Tuff Stuff tank to start with, but since it's 3 inches shallower, I'm concerned that it will have a negative impact on the fish. What are some of your experiences and what would you recommend? Thanks.