How to Get Rid Of Cloudy Water In My Aquarium

Whether you’re a beginner or a pro, when it comes to fishkeeping cloudy water is inevitable. Like with everything in the hobby there’s a reason for everything and it’s no different when it comes to the common issue of cloudy water. The first step you’d need to take is to identify the cause and then start the treatment.
In this article we will talk you through some of the common causes of cloudy aquarium water and what you can do to prevent it.

Bacterial blossom

As a new aquarium goes through an initial break-in cycle, the water can become cloudy or at least a little hazy. It might take several weeks to establish beneficial bacterial colonies that are able to clear waste from the water. Over time, that cloudiness should resolve itself.

Decaying plants or excess food that remains uneaten can also cause the cloudy water seen in bacterial bloom. Keep your aquarium clean by removing any decaying plants or uneaten food. Make sure you do regular maintenance in your fish tank such as vacuuming the gravel regularly and performing partial water changes.

If it is a persistent problem, you may want to think about getting a UV steriliser, which simply kills the microorganisms creating the cloudy aquarium water problem and helps to control algae issues that may cause problems such as green water.

Gravel residue

Gravel residue usually happens within new fish tanks or aquariums that have recently had a substrate change. If the water is cloudy immediately or within an hour or two of filling the tank, it's probably due to insufficiently washed gravel. Drain the fish tank and rinse the gravel until the water runs clear.

Dissolved constituents

If washing the gravel doesn't solve the problem, the next most likely cause of cloudy water specifically in a newly filled fish tank is a high level of dissolved constituents, such as phosphates, silicates, or heavy metals. Using a water testing kit you will be able to see what’s affecting your tank. If you test the water, you'll likely find that the pH is high (alkaline). If this is the case, treating the water with conditioners will often resolve the problem.

Over Feeding

If you find yourself in a constant cycle of returning cloudy water, it may be time to consider cutting down on the amount you feed your fish. Food that goes uneaten will settle into the substrate and start to break down causing a lot of organic waste which is one of the main causes of cloudy water. 

Overstocked Aquarium

It’s important to consider the size of your tank and your fish population when setting up an aquarium. A severely overstocked aquarium may cause stress for the fish as well as increase the likelihood of cloudy water. In simple terms, the more fish you have the more waste they will create.  We recommend to not exceed 1 inch of fish per 3.7 litres of aquarium water.

Sometimes cloudy aquarium water can be a sign of a problem with the algae within your fish tank. To be sure, check out our guide to removing algae from your fish tank to make sure an algae bloom is not you underlying issue.

For more information make sure to have a look at all the articles on our Fishkeeping Advice page.