Clean the area that needs grout, using a hose. This is most commonly between cracked tiles near the edge of or on the inside lip of the pool. Let it dry for an hour.
Push the handle on the end of the pool grout container slowly to squeeze out a thin, steady stream of grout.
Clean the edges of the grout with the putty knife, leaving a smooth surface. Let dry for one hour before it gets wet, and 24 hours before any pressure is applied.