Dish Soap

Dish soap may be used in saturation solutions to minimize the surface tension of water so that bubbles that would clog the saturation tubing can be prevented. Soap allows the water to spread more easily over a surface, and to reduce or eliminate the tendency for the water to bead up on a surface. This characteristic is useful in that the solution can better penetrate the soil it comes into contact with. Another appreciated characteristic of soap in water is that soap does not affect the viscosity of water in any way, so long as the soap is not in extremely high concentrations.

Viscosity tests were performed to support the statement above. They were all done using the same viscometer so the constant used in their viscosity calculations is constant. Times are in seconds

DI H20 + no soap

times: 11.36, 11.32, 11.43

AVG: 11.37

DI H20 + soap

times: 11.38, 11.42, 11.46

AVG: 11.42

Water + HPMC, no soap

times: 41.43, 41.57, 40.96

AVG: 41.32

Water + HPMC, soap

times: 42.78, 41.81, 40.55

AVG: 41.71

What is not known about soapy water is its interaction with soil, especially the fine Nevada sand. More testing may be needed to see if it effects the particle interactions significantly.

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