In 2011, the Black Beauty simple DIY floatation tank was built. Scouring the ‘net for containment tanks, I fell in love with the 325 gallon White containment tank made by Den Hartog:

It looked more elegant, but it is inferior to the containment tank used in the Black Beauty for 2 reasons:

1. it is significantly heavier: it weighs 140 pounds. My friend could not lift it.
2. the plastic is more flappy. The Norwesco plastic does not buckle and swell as easily as the Den-Hartog containment tank.
3. In all fairness, I bought by Den-Hartog tanks from someone who had them out in the sun and rain for about 1 year.

One desirable thing about the Den-Hartog tank is that it is 24 inches high compared to 16 inches high for the Norwesco. This is desirable in terms of not feeling that your face is about to be crunched up against the top containment tank. However, it may or may not be an issue that the added height of the Den-Hartog tank means that it harder to maintain a comfortable temperature.

Here is what I built

Notice the deformity of the top tank. But these tanks came from this outside storage:

Notice how deformed some of them are. And you can see that the lips are not butting up against each other:

Summary of failure

Dont buy used tanks

the sun and rain deform them. Unless you have unconditional money back guarantee

Dont buy tanks that are too heavy for the average person to lift

The Den-Hartog weighs 140 pound. The Norwesco weighs 94 pounds.

If you plan to use a tank for both top and bottom, make sure the lips meet perfectly.