If you could ask the old or the newly born generation, they will confirm to you that they only know of unity candle to be used in most of the wedding ceremonies. It is like this tradition is being broken as many people nowadays have switched to unity sand to be used in their wedding ceremonies. You find that a lot of time had been wasted when using unity candle as even deciding on the one to lit the candle has been a problem as others see it as discriminating the other partner. Prior preparation will be made in wedding sand ceremony to select the best sand with the color which the bride and the groom will like including their family members. Just like other wedding all the normal procedures will be followed to the latter.
In this the bride and the group will have to stand in front of the audience after the officiant has quoted some few words. The officiant will the issue the bride and the groom with the main thing which is sand of different colors depending with the color that they will choose. Not only that, but they will also be provided with one big jar where they will pour their sands to form a mixture. From there he then gives the opportunity for the bride to pour his colored sand to the central jar. After the bride has finished pouring the unity sand sets the groom will them take the opportunity to pour her sand which will now form the second layer. They will do this simultaneously until that time that they would have finished all the sand in their jars.
When this is done, it will be like the couples are now united and the officiant will declare them husband and wife after making an oath to be loyal to one another. This will be followed by a series of activities as planned such as eating together as a family, holding a party where people will dance and drink to celebrate the newly wedded and then going for honeymoon in a place of their choice. Learn more about sands at https://en.wikipedia.org/wiki/Sand_mandala.
Another thing is that in other unity sand ceremony wedding, the family members are also given the opportunity to pour their sand after the bride and groom. This is not mandatory but it depends with the organization of the families that are uniting to form one.
Many people have argued that unity sand strengthens the relationship between the husband and wife. For one this sand will last like forever unless someone decides to interfere with it in one way or the other. Once they see the sand especially during the times when there are quarrels it will be reminding of the past good times they enjoyed.