1. Cut the bottom of the prepared mineral water bottle with a knife, and cut off about half of the bottle body.

2. Dig a small hole in the bottle cap with a multifunctional knife.

3. Wrap the stones, fine sand and activated carbon with gauze and tie them with string. This step is to ensure tight packaging and prevent material leakage.

4. Filled with wrapped stones and fine sand. Put them into bottles in turn, and press them carefully. Do not leave gaps around the bottle, otherwise the filtering effect will be affected.

5. Cleaning the filter layer: take out the big stones, pebbles, fine sand and activated carbon wrapped in the water filter and rinse them with clean water. Then put it into the water filter in turn.

6. Prepare a container to receive filtered water, and prepare a proper amount of sewage to be filtered.

7. Pour the sewage into the filter, slowly pour the sewage into the water filter and catch it with the container below.

8. After waiting for a while, you get the first filtered water. If further filtration is needed, a second filtration can be carried out.

Matters needing attention in making simple filters:

1. When making filters, make sure that the materials used are clean and free of impurities, otherwise the filtering effect will be affected.

2, filling materials, filling in turn, and ensure the material compaction, prevent material leakage.

3. When cleaning the filter layer, be sure to clean it thoroughly, otherwise it will affect the filtering effect.

4. When pouring sewage, avoid sewage overflow and catch it with the container below.

The filtered water is not suitable for direct drinking, so it is better to filter it again.

6. Choose appropriate filter materials: Different filter materials have different filtering effects. When selecting the filter material, it should be selected according to the types of impurities to be filtered and the filtering requirements.

7. Control filtration speed: too fast filtration speed may lead to poor filtration effect, while too slow filtration speed will affect filtration efficiency. Therefore, when making a simple filter, the filtration speed should be controlled reasonably.

8. Replace the filter material regularly: the filter material will gradually lose its filtering effect after being used for a period of time, so it needs to be replaced regularly.

9. Pay attention to safety: When making and using simple filters, pay attention to safety to avoid accidents such as cuts and burns.