To mix grout, pour approximately three-fourths of the amount of water recommended in the manufacturer's directions into a bucket, and add the grout powder. Stir with a trowel, gradually adding water as you stir until the mixture is the consistency of toothpaste or creamy peanut butter.
Make sure all the grout powder is mixed in. Let the mixture rest for five to 10 minutes to allow the water to soak into the powder and the chemicals to activate. Stir the mixture again before using it. The space between tiles determines whether sanded or unsanded grout is needed. Use unsanded grout if the space between tiles is less than one-eighth inch, and use sanded grout for larger spaces.