You might consider at least a third drive in raid for redundancy. This will allow one drive to die, but you won’t be offline while a new disk is shipped.

Only a few gasses are lighter than “air”, but even those have weight. Helium for example weighs 0.0114 lbs per cubic foot.

Helium only rises because it less weight than airz like how oil floats on water.

When your body contains that matter, your weight is higher. When you expel the matter you lose weight.