How much to hydro-test a scuba tank?

In the area of $20-$40

It depends on the size of the tank. The standard tank used at most scuba diving training facilities use an aluminum 80. The tank weighs around 21 lbs. full. As the tank is used during diving it...

Depends on the area - in the Florida Keys/anywhere exotic, expect $10-$15 for air and $15-up for Nitrox. In Daytona Beach, which is the cheapest I have seen, it's $5 for air and $7 for Nitrox. Most...

The amount of air (volume) that any solid container will hold is a function of pressure and temperature. the most common SCUBA tank is an Aluminum 80 which stands for 80 SCF (standard cubic feet)...

Depends on the size of the tank.