Summarize:

A respirator will stop you from accidentally inhaling the tanking dust. Make sure to work in a well-ventilated area by opening windows or doors. Wear a pair of thick gloves so that the tank mixture doesn't get stuck to your hands. If the tanking slurry gets onto your clothes, it will be hard to wash off, so wear an outfit that you can get dirty. You can purchase tanking slurry online or from a hardware store. Read the instructions on the bag so that you know the proper ratio of water to tanking dust. Typically, tanking slurry will need to be mixed at a 4:1 ratio. The instructions will tell you how much tanking slurry is required for the space that you want to fill. Measure the appropriate amount of tanking powder and put it into a plastic bin or bucket. Slowly pour water into the bucket while mixing the solution with a mechanical paddle. Continue to stir the mixture until the mixture is smooth and creamy. If the tanking mixture is too thick, add more water. If the tanking slurry is too thin, mix in more tanking powder.
Wear a respirator, gloves, and a set of work clothes. Read the instructions on the tanking material. Pour the tanking powder into a bucket. Mix the tanking powder with water.