- Gunite Gunite is a term describing a mixture of dry cement mixed with water as it is sprayed into a mold to form pool walls and floor during swimming pool construction.
- Gravity Filter A gravity filter often refers to an entire gravity filtration system, where swimming pool water is fed to the top of a container, and trickles down through a filter medium by the force of gravity.
- Green Algae A common algae in swimming pools, green algae spores enter the pool water, germinate, and attach themselves to pool surfaces; rapidly growing into an algae problem if pool water is not properly sanitized and an algaecide is added on occasion.