Which material filters water the best experiment

[deleted-752002]

Hi! I've been browsing through this website for the past few weeks and I am particularly interested in the "which material filters water the best". I was wondering if I could change up the experiment a bit and wondered if it would still work out so I am in urgent need of an answer. In the original experiment, it says to use food colouring but in different quantities for each water sample. I'm not 100% sure as to why we have to change the measurements for each water sample so I wondering if instead I could make a sand and water mixture but keep the quantities the same for each water sample. Or even if I do use food colouring but I use the exact same quantity for each. I was also thinking of testing out different materials that are generally used to filter water such as sand, gravel, granular activated charcoal and powdered activated charcoal in order to see which one filters water the best. Do you think this idea of mine would work? Oh, and another thing- in the original experiment, before the water gets filtered, it is mixed the material for 10 minutes and only afterwards it is filtered. I've visted other websites and what they did is that they poured the material in the filter and after they put the water (so they basically didn't mix the two together). I was wondering if it would still work if I just skipped the "mixing it together for 10 minutes part" and just did it like the others? I would love to try all of these doubts that I am having but the problem is that our teacher did not give us a due date and we go back to school in about 5 days and I would love to at least have some idea of where I am going. I hope you take some time to read and respond to this- I would really appreciate. Sorry to be bombarding you with questions!

[MadelineB]

Hello Madi and welcome to Science Buddies,

Are you basing your questions on the Science Buddies project?
https://www.sciencebuddies.org/science- ... er#summary

It is good that you are thinking about making changes in the project. However, you might want to think about the hypotheses being tested in the original project compared to the hypotheses you want to test with the modifications you are suggesting.

The Science Buddies project guide has a section called "Constructing a hypothesis" which might help you clarify the different hypotheses:
https://www.sciencebuddies.org/science- ... ience-fair

Another way to help you compare your changes to the original would be to prepare your data table (see the table shown below Figure 6 in the Procedures:
https://www.sciencebuddies.org/science- ... #procedure).

Let us know if these suggestions help you to answer your questions!

~ MadelineB

[probiotics]

Hi Madi!

Don't feel bad about asking questions - questions are great and we're here to help! As Madeline has mentioned, there are quite a few resources available right here on the science buddies website! But I can help you with a few of the more specific questions.

1) Why do we use different concentrations of food coloring?
The different concentrations help represent the different amounts of contamination in water. For example, the water from a sewage system would have a lot more contaminants than water from your sink. In order to test how these filtration methods work on different types of water, we must add different levels of food coloring to each cup. This adds an extra variable to your experiment.

2) Could I make a sand and water mixture but keep the quantities the same for each water sample? If I use food coloring can I use the exact same quantity for each?
I assume that you want to use sand, instead of food coloring, to represent the contaminants. Additionally, you want to keep the level of contaminants the same. Microorganisms in water, which is what we're trying to model, are very very small. Therefore, the molecules of food coloring would probably be a better representation of microorganisms, rather than sand, which might be too large. However, you can keep all the quantities the same. This would just eliminate the variable I mentioned previously.

3) Do you think testing sand, gravel, granular activated charcoal, and powdered activated charcoal in order to see which one filters water the best will work?
Absolutely! These are all common water filters and I think testing their effectiveness would be a great project.

4) Would it still work if I just skipped the "mixing it together for 10 minutes part" and just did it like the others?
I think it would be more effective if you mixed the water filtering compound (like activated carbon) before you poured it into the filter. Mixing them both together allows for the charcoal to more effectively filter the compound, so if you want better results, I would recommend that you mix.

I hope this helped!