The noise from your Aquaclear filter might be due to a few reasons. The leveling device inside the filter can change the GPH output, and this can cause it to run too loudly. Also, the foam that is under the filter can interfere with its operation. There are some things you can try to decrease noise from your Aquaclear filter, including applying vaseline to the impeller.
Application of vaseline to the impeller of your aquaclear filter
Filters that make too much noise can be a problem. In these cases, you may want to check the impeller of your filter. It may not be moving properly or there may be biofilm and slime stuck to it. If this happens, you can apply vaseline to the impeller shaft. This will make the impeller move more smoothly.
If your aquaclear filter is noisy, it might be caused by an unbalanced impeller shaft. This causes noise rattling in your aquarium. The best way to diagnose this issue is to remove the filter lid. If you find that the filter is still rattling, it may be time to replace it.