You will notice in this picture the Mortar has completely deteriorated under the fountain floor stone, turning it into the consistency of sand. This can happen when you use a porous type stone underwater. There are many factors that play a role when choosing the right type of stone for underwater placement such as: stone density/absorption rate, environmental factors, UV Ray exposure, and temperature. For this particular project we have elected to use plaster below the water line instead of going with stone. Using plaster will enhance the appearance and beauty of the water.
Note: Plaster cannot be used above water level, it must remain submerged.
