For this project the client chose both AGT ULTRA Grade Aqua Blue Glow Stones and AGT ULTRA Grade Sky Blue Glow Stones. We recommended both 1/8" and 1/4" sized stone for this project in order to create an interesting '3D depth perception' effect in the glowing concrete surface. We worked with the client on loading rates and glow stone grades. They originally wanted to go with AGT Commercial Grade Glow Stones but we explained that the AGT ULTRA Grade Glow Stones are 30% brighter and longer glowing. So they went with them.