In this Instructable I will show you step by step how to make a water filter that can filter out things like dust but if you want to use it to make pond water clean you's need to boil the water to kill any minuscule creatures that live in the water.
Step 1: Obtaining Your Materials
The materials that I used in the filter were pretty easy to find and most of them relatively cheap. The most expensive material that I used was the activated carbon but it's also a key part of the filter.
Fine/Play Sand: I found this at my local Home Depot but it can be found in other places, the first place you should look is your local home improvement store. I paid $3.98 for a 50 lb bag
Gravel/Pebbles: I also found this at my local Home Depot and it can be found at any home improvement store. It can be obtained from outside but you will have to make sure that they're cleaned very well in order for them to work and not just taint the water you're trying to filter. I paid $4.38 for the pebbles.
Activated Carbon: I obtained this at my local pet store in the fish area. this was the most expensive material on the list costing $15
Step 2: Cutting the Bottle
You will need to cut open the end of the bottle that is opposite of the cap. You need a hole in the bottom so you can put your materials into your bottle, and so you can pour the water you are trying to filter into it
Step 3: Coffee Filter
Before you begin to fill your bottle you should put a coffee filter over where the cap should be to keep everything in and for a bit of extra filtration
Step 4: Filling Your Bottle
You're now going to begin filling your bottle with your materials
1st the cotton balls
2nd the activated carbon
3rd the sand
4th the gravel/pebbles
Step 5: Cotton Balls
The first layer of your filter is your cotton balls.
I advise putting a 1 inch layer of cotton balls
Step 6: Activated Carbon
Next you will add the activated carbon.
I would advise to put an at least half an inch layer, but for my filter I put an inch.
Step 7: Sand
Next you will add your sand, make sure it is fine sand in order for the fiter to work properly.
I advise, again, to make your layer at least half an inch, I made a 1 inch layer.
Step 8: Gravel/Pebbles
Finally, you will add your gravel/pebbles.
I suggest a layer that is at least half an inch but for this project I made a 1 inch layer
Step 9: All Done
You're all done now and it should filter water
The bigger the bottle the more you can repeat this process
Make sure there is about 1-2 inches of free space at the top for the water.
The bigger the filter, the better it filters the water, but you need more water to push through the filter