**6.3. Problem 3: keeping everything in solution**

Sand or ceramic proppants are more than twice as dense as water. Gelling agents and crosslinking polymers are added to the fracking fluid to increase the water's density and help keep the proppants suspended. Various guar formulations are the typical gelling agents. This is the same plant-based material seen as an emollient on processed food. Other plant-based gelling agents are used as well.
