Additive to an aluminum sulfate and water solution to lower pumping pressures I am currently looking for a surfactant (powder form) that I can add to a solution of aluminum sulfate and water.  My current solution is comprised of 34 gallons of water and 4 (four) 50 lbs bag of aluminum sulfate.  It has a specific gravity of 1.275

It is used as an additive to a gypsum based fireproofing product to lower the density as well as help with a quick set of the fireproofing material.  It is injected into the fireproofing material at the base or a 1" hose that is 20 feet long.  I was hoping to find an additive (surfactant?) that would reduce the pumping pressure of the fireproofing material thru the 1" hose without affecting the chemical nature of the aluminum sulfate and water combination.

The aluminum sulfate and water are mixed in a 50-gallon drum with a high propeller blade that is fairly aggressive.  I worry that a normal surfactant will foam up too much and make the product unusable.

If a non-foaming agent can be added to the water that will offer to lower the pumping pressures of the material thru the 1" hose that would be what I am looking for.
The needed pressure depends on liquid viscosity. The significant decrease of water solution viscosity cannot be achieved by adding of minor additives.

It could be achieved by methods that may not be applicable:


Decreasing concentration of the solute
Decreasing viscosity of solvent by different solvent composition
Increasing temperature of solution. A rule of thumb says viscosity decreases by 3% by increasing temperature by $1 ^{\circ}\mathrm{C}$.