Variables in my Experiment

Variables: A variable is any factor that can be controlled, changed, or measured in an experiment. These are the variables in which I needed to change, measure and control whilst completing my experiment: 

Independent variable: The type of liquid (I used four different liquids to experiment with including Coca-cola, Dirty water, Soapy Water and Black Tea)

Dependent variable: The turbidity of the liquids before and after they are filtered (I measure the each liquid before and after it was filtered using a Turbidity Sensor) 

Controlled variables: Same amount of each liquid being filtered, same type of filter (with same amount and type of materials), same amount of liquid used when testing the turbidity, same type of equipment used to measure the turbidity

Variable that needs to be controlled	How this variable will be controlled
Same amount of each liquid being filtered	Use a measuring cup to measure exactly 1 cup of the liquid that you will be filtering.
Same type of filter (with same amount and type of materials) (this includes the amount of filter paper used)	Use the same filter each time you are filtering the different liquids. Make sure you use a measuring cup to measure exactly 1 cup of each material that is made up of the filter.
Same amount of liquid used when testing the turbidity	Only fill the glass bottles up to the line when testing the turbidity of each liquid using a turbidity meter.
Same type of equipment used to measure the turbidity	Only use a turbidity sensor to measure the turbidity of each liquid.