Guide: How To Clear Up A Cloudy Fish Tank

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If your tank resembles a scene from the Walking Dead and your fish look they are floating around in a zombie fog then you’ve got cloudy water, and it sucks!

Below, we have compiled two videos and a few tips to show you how to clear up that cloudy water in your fish tank,

This first video from Howcast gives us an excellent idea of the causes and how you can prevent cloudy water zombie fog.

Video: How To Clear Up A Cloudy Fish Tank

What Causes Cloudy Water In Your Fish Tank?

There are many things that can cause the water in your aquarium to get cloudy, but the most common are:

Bacteria bloom – Note that a bacteria bloom will be a cloudy white. If you notice a greenish colour to the water you may have an algae issue.

You want to decipher between green water and cloudy, milky water. Cloudy is usually bacteria driven. Green is usually algae driven. – Howcast

If you think you may have an algae problem?
Click Here: To see our post on how to prevent and eliminate algae in your fish tank. 

Too much maintenance. Cleaning your filter, big water changes or gravel cleaning can unbalance your aquarium.

When this happens bacteria can take up in the water and start feeding off the nutrients now floating in the water column.

Typically, the water will settle with time and the milky appearance may disappear. However, you can take steps to speed things up one of two ways;

You Can Try A UV Sterilizer

A UV Sterilizer will stop the bad bacteria by using ultraviolet light to cause mutations in the bacteria’s genetics so they can’t reproduce. In most cases the UV sterilizer will create crystal clear water conditions within 3-6 days.

Watch the video below where you can see time-lapse video of exactly how a UV Sterilizer works, day 5 is amazing.

Will a UV Sterilizer Clear Up Cloudy Water? (Video)

Below is an awesome video from Eddie’s How To’s that shows us actual time-lapse proof over  a 5 period how a 9Watt SunSun UV Sterilizer eradicated the cloudy water in his fish tank.

Note: @1:55 you can start to see the transformation and @2:14 you can see the complete transformation where the cloudy water is gone.

Video: How do You Clear Up a Cloudy Fish Tank?

You Can Add Some Beneficial Bacteria

Adding beneficial bacteria to your aquarium will help colonize beneficial bacteria in your gravel, rocks, plants, filter media. This beneficial bacteria will eventually out-compete the bad bacteria for the nutrients now in the water column.

After the cloudy water is gone if you still notice some particles floating around, you can add a coagulating agent like Seachem Clarity, which will cause most of the particles to stick together and allow your filter to pull them out of the water.

Otherwise, keep to your weekly maintenance and everything should balance itself out.

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By |2018-03-28T19:11:56+00:00March 28th, 2018|Aquarium Maintenance|Comments Off on Guide: How To Clear Up A Cloudy Fish Tank

About the Author:

Jack Dempsey has over 20 years of experience with freshwater aquariums, his goal is to help beginners avoid the biggest mistakes when getting started. If you find something helpful please share it on your favourite social network. If you need help with anything send Jack a question.