Discussion

In reference to that shown in the results the outcome of my experiment was relatively what i had predicted in my hypothesis and expected. I measured turbidity of the filtered and non-filtered liquids and then calculated and graphed the difference between the average turbidity’s of the filtered and non-filtered liquids. At the end of my experiment the average difference between the filtered and non-filtered dirty water was 671.2NTU, the black tea was 84NTU, the Coca-Cola was 56.5NTU and the soapy water was 131.1NTU. The turbidity of the dirty water will change the most drastically when it is filtered, followed by the soapy water, then the black tea and finally the cola-cola. There is not evident trend from my results although, it can be assumed that the turbidity’s of the liquids that had larger particles in them (such as the dirty water and the soapy water- dirty particles and bubbles made from the detergent- as shown in the picture below) changed more drastically when filtered than the liquids (Coca-Cola and black tea) in which had dissolved particles in them. 

Reliability: I only completed my experiment twice which may have led to unreliable results. This experiment should be repeated several time to ensure the same result is obtained using the same method. Further testing could have been carried out to ensure reliable results. I carried out two experimental tests for my experiment, however for extremely reliable results I could have done a further test, in which would have created more accurate outcome/results of my experiment. 

Accuracy: In order to effectively improve the accuracy of this experiment, the equipment used for testing could have been more accurate. I have not used a turbidity meter before and thereby was not familiar with this sort of technology. Although I was shown a demonstration on how to use the turbidity meter I could have done more research and become more familiar on how to use the turbidity meter, thereby using it to its full potential. When I washed the sand and the gravel I used my hands and cleaned as much dirt and other unwanted particles out of these materials, although some particles of dirt may still be presents in these items. To improve the accuracy of the cleaning of these materials I could have repeated the cleaning process numerous times, and after each time letting the water drain out of the materials. This will improve the purity of the sand and the gravel, in which if they still have unwanted dirt in them, could affect the results/outcome of my experiment as these dirt particles could drain into the filtering liquids, affecting the turbidity. 

Validity: To effectively improve the validity of this experiment, all variables needed to be controlled. The measurements of the components of my natural water filter (sand and gravel) should be controlled to prove fair results, although whilst measuring these liquids I may have been rushing and estimated different amount of liquids. This could affect the filtering capability of my natural water filter, causing my results to be invalid. In order to overcome this issue I need to take more time when measuring the amount of materials I need for my experiment, thereby proving more valid results.