Do not use a column that is longer than your arms. 

I do recommend using the same rules of field capacity test.

Firstly you must make boundary conditions to your study case . If the study rely on sedimentation then use the column test. If the study is on toxicity of heavy metals then rely on the floc tester .To build a model you must rely on simulation for physical chemical processes .Biological processes rely on past experience in modeling as the bacteria cannot be modeled.