Maybe you wake up one day and you see the water strange. Of these times that you wonder what could have happened so that the water is that way if you have not done anything different in your day to day or with the fish. Often this can come from a failure in the aquarium air pump, either that it is too dirty, or that it begins to fail (which can happen).
For one reason or another, the first solution we can take in this situation is to empty, not an aquarium room, but two quarters, to replace cloudy water with good water. I advise you to take the opportunity to clean the bottom by removing the water from the bottom, that is, as if you were substituting for a quick cleaning.
The next step is take out the filters and the pump to clean it well. It may be that those filters are also dirty and that is why everything has become cloudy. However, if the pump has algae or products in the inner tube then I can tell you that it would be best to completely empty the aquarium.
The fact of having foreign bodies in the pump tube makes us suppose that there may be algae inside the compartment where the filters and the pump are housed and that, after two or three days, will have us back with the water cloudy.
Once all the water has been replaced, it is advisable to add anti-algae products to prevent their formation as well as a product to remove chlorine from the water and also to create bacteria in it.
In pet stores they also sell a product what can be thrown to clarify the water. I have tried it and it has not given me much result but you can try it yourself. They usually have 24 hours to fully run being able to repeat after those hours a second time before recommending you empty the aquarium.