You could use a filter or if the water is muddy you can also use the method of sedimentation.
filter
There is dirty water all over Africa. It's not easy to keep rivers clean,or to filter water.
To make a water filter using a water bottle, you can cut the bottom off a plastic bottle and fill it with layers of sand, gravel, and activated charcoal. Pour dirty water through the top of the bottle, and the filter will clean the water as it passes through the layers.
when the water starts to get dirty if it is a bit dirty then leave it when it starts to get really dirty clean the filter and your fish tank
The principle is 'dilution': with the first addition of clean water to dirty water, the dirty water becomes less dirty because it is diluted by the clean water. With the continued addition of clean water to dirty water, eventually the dirty water will be completely diluted and there will be no dirty water left; it will all be replaced by clean water.
The filters are either ver dirty or clogged which wont allow the water to filter properly. I recommend that you replace the filters.
Rainwater is generally considered clean as it falls from the sky. However, it can pick up pollutants and contaminants as it travels through the air and lands on surfaces, making it potentially dirty depending on the environment it passes through. It is always advisable to collect and filter rainwater before consuming or using it for various purposes.
to clean dirty water it needs to be cleaned or filtered
You can use clean tap water for your goldfish, but not dirty or used water.
To ensure your water is safe to drink using a clean filter, regularly replace the filter according to the manufacturer's instructions and follow proper maintenance procedures. This will help remove contaminants and ensure the filter is working effectively to provide clean and safe drinking water.
clean water is naturally dirty, it goes through a process in which then it becomes clean.
dirty