Researchers studied how to clean slightly dirty water using a combination of chemicals and a special filter. They found that the amount of chemicals and the pH level were important for cleaning the water. Filtering the chemicals along with the water worked better than filtering just the water. They also tested different chemicals and found that one was better at removing dirt from the water, while another was better at keeping the filter clean. They discovered that most of the dirt on the filter was from a layer of dirt, followed by tiny organisms, and then some other types of dirt. They also found that flushing the filter with clean water helped it work better.